MESSAGE 



GOVERNOR OF MARYLAND, 

TRANSMITTING THE 

REPORTS OF THE JOINT COMMISSIONERS, 

AND OF 

/ 

■ • / 

LT. COL. GEAHAM, U. S. ENGINEERS, 

IN RELATION TO 

THE INTERSECTION OF 

THE BOUNDARY LINES 



STATES OF MARYLAND, PENNSYLVANIA, & DELAWARE. 




WASHINGTON: 
PRINTED BY GIDEON AND CO. 

1850. 



MASON AND DIXON'S LINE 



State Department. 
Annapolis, Md., March 7th, 1850. 
To THE General Assembly : 

Henry G. S. Key, Esquire, of Saint Mary's county, 
was appointed by me on the 21st of August last, a com- 
missioner under resolution No. 18 of December session 
1845, to ascertain and refix, in conjunction with Joshua 
. Eyre, Esquire, a commissioner appointed on the part 
)f Pennsylvania, and George Read Riddle, Esquire, a 
3ommissioner appointed on the part of Delaware, certain 
boundaries where the States of Maryland, Pennsylvania 
and Delaware join each other. The commissioners have 
performed this duty in a very able and satisfactory man- 
ner ; and the accompanying report and papers, and the 
map of the boundaries adjusted and fixed by them, pre- 
pared by Lt. Col. James D. Graham, of the U. S. TopL 
Corps of Engineers, detailed by the War Department for 
this particular service, at the request of these States, 
respectively, which have just been received at this De- 
partment, are herewith transmitted for such disposition 
as to the Legislature may seem proper. 

PHILIP F, THOMAS. 



By the Senate, March 9th, 1850. 

Resolved hy the General Assembly of Maryland, That 
Ms Excellency the Governor be requested to cause to be 
printed, The report and accompanying documents relating 
to the boundary line between this State and the States 
of Pennsylvania and Delaware, communicated to the 
Senate in his message of the 7th instant. 

Resolved, That his Excellency the Governor be and is 
hereby authorized to place temporarily in the custody of 
Col. J. D. Graham, United States Topographical Engi- 
neers, recently employed in retracing certain portions of 
the conterminous boundaries of Maryland, Delaware and 
Pennsylvania, the manuscript proceedings of the com- 
missioners and surveyors, including those of Mason and 
Dixon, which relate to the demarcation of the ancient 
boundaries between Maryland and Pennsylvania, in con- 
formity with the several agreements between Cecilius 
Lord Baltimore and Wm. Penn, and their heirs and suc- 
cessors, together with said articles of agreement, to enable 
the said Engineer to make such reference to said docu- 
ments as may be requisite to illustrate his report on said 
boundaries to the Topographical Bureau. 

Provided, the said document shall be returned to the 



archives of the State, on or before the first day of Jan- 
uary, 1851. 

By order, 

JOS. H. NICHOLSON, Glerh. 

By the House of Delegates, 

March ^th, 1850. 
Read and assented to 

By order, 

G. G. BREWER, Glerh. 

We hereby certify that the foregoing is a full and true 
copy of Resolution No. 94, which was read and assented 
to by the General Assembly of Maryland at its Decem- 
ber Session, 1849. 

Given under our hands at the City of Annapolis, on 
the 11th day of March, A. D. 1850. 

JOS. H. NICHOLSON, Glerh of the Senate. 
GEORGE G. BREWER, Glerh House Del. Md. 



City of WashingtoNj March 1, 1850. 

To their Excellencies P. Francis Thomas, Governor of Maryland, 
William F. Johnston, Governor of Pennsylvania, and 
William Tharp, Governor of Delaware : 

The undersigned commissioners, appointed by your 
Excellencies in pursuance of the legislation of our re- 



6 

spective States, for ascertaining and refixing certain 
boundaries where the States of Maryland, Pennsylvania 
and Delaware join each other, beg leave to make the fol- 
lowing report : — 

Early in October last, we individually and in joint 
consultation, sought the information necessary to the 
discharge of our duties, and after conference in the city 
of Wilmington, saw that much science and many intri- 
cate mathematical problems were involved, that not only 
required the talents of men as commissioners distin- 
guished in the annals of our country, and surveyors, to 
carry out the agreement of the proprietary governments 
in 1760, but finally enlisted the services of those distin- 
guished mathematicians, Messrs. Mason and Dixon. 

The work before us involved the important points 
where the peninsular or tangent line intersects the due 
north line, and where the curve, on a radius of twelve 
English statute miles from New Castle, was required to 
begin ; also, the intersection of said curve with the due 
north line, or the point where the three States join each 
other, and the intersection of the north line with the 
parallel of latitude — being the north-eastern corner of 
Maryland, or boundary of Pennsylvania and Maryland 
on the north. 

Looking to the intricacy of the work and the distinc- 
tion of our predecessors, the undersigned sought, through 
your Excellencies, assistance from the General Govern- 
ment. The Secretary of War promptly afforded it in 
the detail of Lieut. Col. James D. Graham, of the corps 
of Topographical Engineers, alike distinguished for the 



corps to which he belongs, and signal ability with which 
he had executed many national works. 

After a full inquiry into the subject, and studious 
examination of the public archives at Annapolis, where 
alone they were to be found in preservation, and copious 
extracts and notes from all connected with the agree- 
ment of the proprietary governments of 1732 and 1760^ 
by Col. Graham, and the undersigned, we met Coh 
Graham again in New Castle, Wilmington and Newark, 
Delaware, for observation, conference and reconnoissance ; 
when, for the purpose of a proper understanding of our 
respective duties, the accompanying correspondence, 
marked A, B, and C, was had. It resulted in an ex- 
perimental survey, under the direction of Col. Graham, 
with a full corps of assistant engineers, and such men, 
for field labor, as were required by him and approved by 
the undersigned. 

This experimental survey, the undersigned were grati- 
fied to find, resulted most satisfactorily, so far as land- 
marks, remaining monuments, and supposed positions for 
some of the lost monuments were involved ; and we 
hoped that it might be final, and would close our labors ; 
but the computations and plotting developed great dis- 
crepancies between our work, and that of the former 
commissioners and Messrs. Mason and Dixon, both in 
measurement and the true position of the tangent point. 

The measurement, too, of the radius, or distance from 
the centre of New Castle to the aforesaid tangent j)oint, 
involved consequences important to Maryland, Pennsyl- 
vania and Delaware, as well as the correct running of 



the curve, and determined us, on full consultation with 
Col. Graham, to prosecute a system of triangulation that 
would explain all discrepancies, afford accuracy to the 
different measurements, and supply the true distance 
from the steeple of the court house, at New Castle, to 
the aforesaid tangent point, or to any part of the said 
curve. 

This work was entered upon and prosecuted with great 
diligence, and would long since have been completed but 
for unsettled weather, which retarded the field labor, in- 
terrupted instrumental observations, and detained the 
engineers upon the line from the 15th day of November 
to the 7th day of February. 

On the 8 th day of February, all the field hands were 
discharged, and Col. Graham, with his assistants, repaired 
to this place to complete their computations, and make 
out such report and maps of the work as would afford to 
all a correct view of the labor they had encountered, and 
designation of an important portion of the territorial 
limits of our respective States. 

The undersigned, having determined to meet at this 
place as soon as their presence was necessary to a final 
adjustment of accounts and signing of maps, as well as 
for an interchange of views as to their joint and several 
reports, soon ascertained, that while their stay would ex- 
pedite the result, it would be marked with a delay com- 
mensurate with all their early misconceptions of the work. 
We are, however, gratified with the belief that constant 
and daily intercourse with Col. Graham, has better ena- 
bled us to appreciate the continued extent of labor, and 



9 

precise scientific execution, that must ensure the confi- 
dence of the scientific world, all of which will be properly 
estimated by your Excellencies on examining the map 
and report of the Engineer, from which we will not fur- 
ther withdraw your attention, and which are submitted 
as the result or our commission. 

We have the honor to be, 

Respectfully yours, 

H. G. S. KEY, 

Commissione7' on the part of Maryland. 

JOSHUA P. EYRE, 

Commissioner on the part of Pennsylvania. 

GEO. READ RIDDLE, 

Commissioner on the part of Delaware. 



(A.) 



Wn.MiNGTON, Delaware, November 12, 1849. 
To Lt. Col. J. D. Graham, 

Of the IT. S. Topographical Engineers; 

Sir — The undersigned, commissioners on the part of 
the States of Maryland, Pennsylvania, and Delaware, 
appointed for the ascertainment of the boundary, or point 
of intersection where the three States join each other, 
and such other boundaries of the said States as are ne- 
cessary to accuracy in refixing and establishing the same, 



10 

are ready, under your assistance, to proceed with the 
work ; and, looking to your experience for the mode or 
instructions by which the field operations are to be con- 
ducted, ask you to furnish a detailed plan thereof for 
the approval of the board, and accomplishment of the 
purposes of our respective States. 

Permit us further to add, that, if found necessary to 
accuracy in ascertaining the above point, it is our pur- 
pose to refix such stones as may be broken or lost with 
new stones or monuments, particularly at the following 
points, viz:— 

1st. The beginning of the curve or north end of the 
tangent line. 

2d. The meridian of the curve between Delaware and 
Maryland. 

3d. The point or place of intersection of the due north 
line and the said curve, being the point of intersection 
of the three States; and 

4th. The north end of the aforesaid due north line, 
or intersection of said line with the east and west line 
of Mason and Dixon, being "a parallel of latitude fifteen 
Enghsh statute miles south of the most southern part of 
the city of Philadelphia," and the boundary of Pennsyl- 
vania and Maryland on the north. 

Respectfully, 

H. G. S. KEY, 

Commissioner on the part of Maryland. 

JOSHUA P. EYRE, 

Commissioner on the part of Pennsylvania. 

GEO. READ RIDDLE, 

Commissioner on the part of Delaware. 



n 



(B.) 



Newakk, DELAWARE; November 15, 1849. 

Gentlemen : — I have the honor to acknowledge the 
receipt, on the 12th hist., of your joint communication 
of that date, requesting me to present, for the approval 
of your board, a detailed plan of operations for the ascer- 
tainment of the boundary or point where the States of 
Maryland, Pennsylvania, and Delaware join each other, 
and such other boundaries of the said States as are ne- 
cessary to accuracy in refixing and establishing the same. 
Having, in company with your board, made an examina- 
tion of a portion of the boundaries extending from the 
north-east corner of Maryland, two or three miles south 
of the tangent point, or point of contact of the peninsu- 
lar line with the periphery of the circle of twelve miles 
radius from the centre of New Castle, I now respectfully 
submit to you the following suggestions : — 

It appears that the junction of the boundaries of the 
three States, is at the northern intersection of the above- 
named circle, with the meridian line running due south 
from the north-east corner of Maryland, and that the 
said meridian line again intersects the circle at a point 
one mile and seven hundred and ninety-three yards and 
three-tenths of a foot due south of the preceding point. 
This last-mentioned point is the tangent point, or point 
of contact of the peninsular line with the said circle. 



12 

If this tangent point can be identified with certainty 
upon the ground, having the direction of the tangent 
line well marked by monuments already found, the por- 
tion of the circle in question can, very readily, be traced 
and continued, until its cord shall coincide with the me- 
ridian line already named, which will give the point 
required. 

If the stone which was originally placed to mark the 
tangent point is missing, it will be desirable to find that 
point, and replace the stone monument upon it, as a 
point of beginning to trace the curve. This may be 
done by prolonging the direction of the tangent line, de- 
duced from any two monuments found upon it, until 
the direction of the line perpendicular to it shall pass 
through the centre of the circle of twelve miles radius, 
which is understood to be the steeple of the court house 
at New Castle ; or this tangent point, and also the point 
of junction of the three States, may be fixed by prolong- 
ing, trigonometrically, the true meridian direction from 
the north-east corner of Maryland due south, until the 
required distances, obtained from the original surveys of 
Mason and Dixon, of three miles and nine hundred and 
ninety-nine and nine-tenths yards, and five miles and 
thirty-three yards from the said north-east corner of 
Maryland, shall be reached. 

The meridian direction must, in that case, be obtained 
by astronomical observations with a transit instrument 
and good chronometers, and the triangulation be executed 
with a good theodolite, adapted to nice geodetic opera- 
tions, all of which I already have at my command. 



13 

But the first step in the operation I conceive to be, to 
cause a rapid experimental survey to be made with the 
chain and small transit theodolite, that shall lay down 
all the monuments now existing, from some point one 
or two miles south of the tangent point, to the north- 
east corner of Maryland. When this survey is plotted, 
we shall be enabled to show all the monuments now 
existing on the ground, and, by comparing their dis- 
tances apart, with those given in the notes of survey of 
Messrs. Mason and Dixon, to ascertain what monuments, 
if any, are missing; and then we shall be enabled to as- 
certain likewise, with precision, according to the most 
applicable of the methods above suggested, the points 
they should occupy, and hence proceed to erect them 
under your immediate supervision. 

If it meet your approbation, we will proceed at once 
with the preliminary survey. 

I remain, gentlemen, 

Very respecfully, 

Your obedient servant, 

J. D. GRAHAM, 

Lt. 061. Topographical Engineers. 

To Messrs. H. Gr. S. Key, Joshua P. Eyre, Geo. Kead Riddle, Com- 
missioners, &c. &c. &c. 



14 



(C.) 

Newark, Delaware, November 15, 1849. 

To Lt. Col. J. D. Graham, 

United States Topographical Corps of Engineers : 

Sir — We have duly received and considered your 
communication of this day, in reply to ours of the 
twelfth instant, dated at Wilmington, and take pleasure 
in saying, that we concur in your views and plans for the 
operations necessary to the purposes of our respective 
States. 

The extent of work intimated in your communication, 
is about what we presumed was indispensable to accu- 
racy, from our early examination of the archives of our 
States, connected with the operations of Messrs. Mason 
and Dixon, and the observations we had made on a pre- 
vious examination of much of the lines that might be 
the field of our labors; and that the main points maybe 
so marked with a view to future permanency, we pro- 
pose to mark with stones or monuments as follows : — 

1. The tangent point, or north end of the tangent 
line, shall be marked with the letters TANGENT, and 
with the letter M on the side next to the State of Mary- 
land, and the letter D on the side next to the State of 
Delaware. 

2. The meridian of the curve shall be marked, on the 
side next to Maryland, with the letter M, and shall be 
oval on that side; and shall be marked on the side next 
to the State of Delaware, with the letter D. 



15 

3. The point or place of intersection of the due north 
line and the curve — being the point of intersection of the 
three States — shall be marked with a stone of triangular 
shape, and the letters M, P, and D, on the sides towards 
the respective States of Maryland, Pennsylvania, and 
Delaware, and also with the names of the commissioners 
on some side thereof 

4. The north end of the aforesaid due north line, or 
intersection of said line with the east and west line of 
Mason and Dixon, being the boundary of Pennsylvania 
and Maryland on the north, shall be marked as follows : 
On the sides next to the State of Maryland with the let- 
ter M, and on the sides next to the State of Pennsyl- 
vania, with the letter P. 

We also propose, that all the said stones, or monu- 
ments, shall have 1849 inscribed on some side thereof 
and be fixed at least four feet deep in the ground, and 
shall show at least thirty niches above the ground. 

We beg leave further, most respectfully to suggest, 
that the progress of your operations may present modifi- 
cations, which will be considered, by you and ourselves, 
with due regard to the objects to be attained. 

We have the honor to be. 

Respectfully yours, &g. 
H. G. S. KEY, 

Commissioner on the part of Maryland. 

JOSHUA P. EYRE, 

Commissioner on the part of Pennsylvania. 

GEO. READ RIDDLE, 

Commissioner on the part of Dela/ware. 



COL. GRAHAM'S REPORT TO THE COMMISSIONERS. 



Washington, Februari/ 27, 1850.. 

To Messrs. H. Gr. S. Key, Joshua P. Eyre and George Kead Riddle^ 
Commissioners for adjusting and refixing certain parts of the boundaries 
of the States of Maryland, Pennsylvania, and Delaware : — 

Gentlemen : — Having been invited by you, in Novem- 
ber last, to conduct the surveys and examinations neces- 
sary to the elucidation and adjustment of certain portions 
of the conterminous boundaries of your respective States, 
known as " Mason and Dixon's line," for which purpose 
you were appointed commissioners by the Governors of 
those States, under authority of recent legislative enact- 
ments, I have the honor now, in pursuance of a confer- 
ence with you upon the subject, to lay before you a re- 
port, showing all that has been done in the field, and 
which will serve to show, and enable you to decide, what 
more ought to be done, by authority of further legislation, 
to complete the demarcation of the boundaries of two of 
these conterminous States; namely, Pennsylvania and 
Delaware. 

As soon as the maps showing the surveys we have 
already made, can be completed, which I understand you 
wish to lay before your respective State authorities with 
2 



18 

as little delay as possible, I propose to make a more full 
report, embracing such notices as will present a general 
view of the scientific operations of Messrs. Mason and 
Dixon, and of their predecessors, in tracing the various 
lines which now constitute important portions of the 
boundaries of those- States. This report will be duly 
communicated to you when completed. 

In pursuance of authority from the bureau of topo- 
graphical engineers, I repaired, on the 30th of October 
last, to Annapolis, to confer with the Governor of Mary- 
land, in reference to the duty which relates to the verifi- 
cation of certain points in the boundary between the 
States of Maryland, Delaware, and Pennsylvania, and 
to investigate the notes of Mason and Dixon, which were 
understood to be in the archives of the State of Mary- 
land. 

These documents, together with the articles of agree- 
ment between Charles Lord Baltimore, and the heirs 
and successors of Wilham Penn, of the 10th day of May, 
1732, and of the subsequent agreement between Frede- 
rick Lord Baltimore, and Thomas and Richard Penn, 
the surviving heirs of William Penn, entered into the 
4th of July, 1760, and also the records of the proceed- 
ings of their commissioners and surveyors, from time to 
time duly appointed, all in manuscript, were placed at 
my disposal by his Excellency, Philip F. Thomas, Go- 
vernor of Maryland. These manuscripts embrace a 
periqd of near thirty-seven years ; namely, from May 
10th, 1732, to the end of the year 1768. From them 
such extracts and brief minutes were made as were 



19 

deemed requisite to a proper understanding of the lines 
to be examined. 

The articles of agreement finally entered into between 
the parties, and their instructions to their commissioners, 
define clearly the lines of boundary between the then 
provinces of Maryland and Pennsylvania, in conformity 
to the memorable decree of Lord Chancellor Hardwicke, 
pronounced the 15th of May, 1750, which set at rest 
for a time, and was the basis of the final settlement of 
a dispute that had lasted many years, between the pro- 
prietaries, as well as the border inhabitants, of these two 
provinces. 

Without quoting these articles at length, it will be 
sufficient here to state that the boundary between the 
two provinces was thus required to be run, namely : to 
begin at Cape Henlopen, and run a line due west to a 
point midway between that Cape and the shore of Chesa- 
peake Bay. 

From this middle point a line was to be run northerly 
in such direction, that it should be tangent to a circle 
whose centre was decided to be the centre of the court 
house* at New Castle, and whose radius should be twelve 
English statute miles, measured horizontally. From the 
tangent point of contact of the northerly line with the 

* See the old parchment containing the agreement of May, 1760, and 
the instructions from the commissioners to the surveyors, given at New 
Castle, the 7th of November, 1761, contained in the proceedings of the 
commissioners, in manuscript, at Annapolis. They specify the exact 
point for the centre of the circle, as well as the length of, and manner of 
tracing out the radius. 



20 

periphery of the circle, the line was to he continued due 
north until it should reach a point fifteen English sta- 
tute miles, measured horizontally, south of the parallel 
of latitude of the most southern point of the city of Phi- 
ladelphia.* 

From the northern extremity of the said due north 
line, a line was to be run due west, continuing upon a 
parallel of latitude until the western limits of Maryland 

* The following is an extract from the proceedings of the commission- 
ers, convened at Philadelphia, under date of December 3, 1763 : — 

" The commissioners met according to adjournment. 

" Present as yesterday, and also Benjamin Chew, Esq., another of the 
commissioners for Pennsylvania. 

" The commissioners having, in consequence of their agreement of yes- 
terday, requested the JMayor and Recorder, and some of the persons ap- 
pointed to lay out lots and regulate water courses in the streets of the 
said city, which office requires that they should be men well acquainted 
with the exact situation of the several streets, and the dimensions of the 
several squares and lots of ground therein, to show them which is the 
most southern part thereof. The said IMayor and Ptecorder, and two of 
the said regulators, to wit : Alderman Rhoades and Mr. Jacob Lewis, 
went with the commissioners and Messrs. Mason and Dixon, to the street 
called Cedar, or South street, the south side of which street the said 
Mayor, Recorder, and Regulators informed the commissioners is, and, as 
they verily believe, ever has been, from the time the said city was first 
laid out, deemed and taken to be the southern boundary and limit there- 
of, and to which boundary the IMayor, Recorder, and Aldermen of the 
said city have constantly exercised jurisdiction; by which information, 
and a view of some old deeds that were produced by persons possessed of 
lots bounding on the said Cedar street, and of a plat of the said city, the 
comniissioners were all satisfied that the north wall of a house, at this 
time occupied by Thomas Plumsted and Joseph Huddle, is the most 



21 

and Pennsylvania should respectively be reached, which, 
in the case of Pennsylvania, was defined to be five de» 
grees of longitude west of the river Delaware. 

The conclusion of the eighth article of the agreement 
of 1732, which is incorporated into the instructions of 
Lord Baltimore, and John, Thomas, and Kichard Penn, 
to their respective commissioners, dated the 12th of May, 
1732, and repeated in all the subsequent instructions, 
provides that " in case said north hne from the tangent 
of the circle of New Castle, shall break in upon the said 
circle, in such case, so much of the said circle as shall 
be cut off by the said Hne, shall belong to, and be part 
of the county of New Castle.'"'' 

southern part of the said city of Philadelphia. The commissioners then 

adjourned to Monday morning, at ten o'clock. 

J. EIDOUT, JAMES HAMILTON, 

JNO. LEEDS, • EICHAED PETEES, 

JOHN BAECLAY, BENJAMIN CHEW, 

GEO. STEUAET, WM. COLEMAN, 

DAN. OF ST. THOS. JENIFEE, JNO. EWING." 

Note 2. — The latitude of the north wall of this house, occupied ia 
1763 by Thomas Plumsted and Joseph Huddle, was determined by 
Messrs. Mason and Dixon, from astronomical observations, in 1763-64, 
with a zenith sector, to be 39° 56' 29" .1. The point, fifteen English 
statute miles due south of that parallel, was computed by Messrs. Mason 
and Dixon, to be in latitude 39° 43' 18". From our knowledge of the 
dimensions and figure of the earth, we should at this day compute it to 
be in latitude 39° 43' 26" .3. J. D. G. 

* It seems to have been doubtful, when these articles were drawn, 
whether the direction of the tangent line would be north-westerly or 



22 

In pursuance of the decree of 1750, commissioners and 
surveyors were appointed to run the required Hues. In 
1751, a line was traced due west from Cape Henlopen 
to the shore of Chesapeake Bay, and its length ascer- 
tained, by measuring with a chain, to be sixty-nine miles 
and two hundred and ninety-eight perches. At the dis- 
tance of sixty-six miles and twenty-four and one-half 
perches from the point of beginning, Slaughter's Creek 
was reached, and here Lord Baltimore's commissioners 
contended the line should end; but those on the part of 
the Penns insisted that it should be extended to the 
eastern verge of the bay. 

In April, 1751, Charles Lord Baltimore died, and the 
demarcation of the boundary was suspended. His heir 
and successor, Frederick Lord Baltimore, raised objec- 
tions to the decree of 1750, and determined to resist its 
execution, which brought on a new controversy between 
the proprietaries. Before a decree was had upon it, an 
agreement was entered into between the parties on the 
4th of July, 1760, which, in fact, adopted the points that 
had been previously settled by the agreement of May 
10th, 1732, and the decree of May, 1750, as to the lines 
defining the boundaries. The proceedings of the former 
commissioners were also recognized by this agreement, 
and confirmed by it so far as they were conclusive. 
Cape Henlopen was determined to be the point previ- 
ously fixed upon as marking this cape, and the termina- 

nortli-easterly from the middle point of the west line run from Cape Hen- 
lopen to the shore of the Chesapeake Bay. 



23 

tion of the due west line from thence across the penin- 
sula, was decided to be that which had been contended 
for by the commissioners of Pennsylvania ; and the mid- 
dle point of that line, from whence the tangent line was 
to start, was decided to be thirty-four miles and three 
hundred and nine perches from the point of beginning 
at Cape Henlopen. 

At the middle point of this peninsular line, a bound- 
ary stone was to be planted at their joint expense, 
marked on the south and west with the arms of Lord 
Baltimore, and on the north and east with the arms of 
the Penn family, graven thereon. 

Commissioners were required to be appointed by each 
of the parties within thirty days after the execution of 
this agreement, to carry its provisions into effect. This 
was accordingly done, and the said commissioners met 
at New Castle, the 19 th of November, 1760, and imme- 
diately entered upon the discharge of the duties commit- 
ted to them. 

The hnes, as they were traced and approved by the 
commissioners, were marked and defined by posts of cut 
stone, about four feet long, and ten to twelve inches 
square, placed at the distance of one mile apart. These 
stones were prepared in England, and sent over to Ame- 
rica from time to time, as the lines progressed. Every 
fifth mile stone was engraved with the arms of Lord 
Baltimore on the side facing towards Maryland, and 
with the arms of the Penn family on the side facing to- 
wards Pennsjdvania. 

The agreement of 1732 stipulated, and it was ordered 



24 

in the decree, by the Lord High Chancellor, that the 
bounds should be marked with the arms of the proprie- 
taries on the sides facing towards their respecting ter- 
ritories. 

The other mile stones were engraved with the letter 
M on the sides facing Maryland, and with the letter P 
on the sides facing Pennsylvania. 

From November, 1760, to the latter part of October, 
1763, the commissioners and surveyors were laboring in 
attempts to trace out the radius of twelve miles, and the 
tangent line from the middle point of the west line across 
the peninsula. The measurements were all made with 
a chain of sixty-six feet, divided into one hundred links, 
except alone that a triangulation was extended a short 
distance from the court house at New Castle, in running 
out the radius, in order that the true point of departure 
should be the steeple or centre of that building, which 
could not be reached with the chain. The surveyors 
were required to compare their chains with a standard 
measure as often as might be necessary, to reduce the 
chaining to accurate measure. 

Several experiments were made to approximate to a 
proper junction of the radius of twelve miles, with a true 
tangent line, from the middle post. In this protracted, 
tedious, and expensive operation, vistas were required to 
be opened along all the lines traced through the dense 
forest that then overspread the country. 

The rectilinear directions were attempted to be pre- 
served by setting up poles or staves in line, as the work 
progressed. 



25 

As late as the 21st of October, 1763, no practical so- 
lution of this problem had been effected, although, as 
was afterwards ascertained, a close approximation to the 

true tangent point had been reached, 

M 

A post marked ^jj had been planted at the extrem- 
ity of a line traced for a radius, west from the court 

house at New Castle ; and two other posts, one marked 

T 

^jj and the other marked TP, had been planted at the 

northern extremities of lines traced for a tangent. Each 
of these three posts was supposed, when planted, to ap- 
proximate very near to the true tangent point. 

In the proceedings of the commissioners, under date 
of October 22, 1763, we find the following minute, viz : — 

•' The commissioners having taken into consideration 
the agreement entered into by them at their last meet- 
ing, to represent to their respective constituents what 
lines had been already run, after what manner, and what 
had been the issue, in order that they might give the 
necessary directions for running and ascertaining the 
tangent line, the Pennsylvania commissioners informed 
the Maryland commissioners that they had lately received 
a letter from the proprietors of Pennsylvania, dated the 
10th of August last, acquainting them that they and 
Lord Baltimore had agreed with two mathematicians, or 
surveyors, to come over and assist in running the lines 
agreed on in the original articles, who were to embark 
for Philadelphia the latter end of August last, and that 
their arrival might soon be expected. Whereupon, the 
commissioners were of opinion that it was better to delay 



26 

making the representation to their constituents, according 
to their former proposal, until the arrival of the said 
mathematicians^ 

"The commissioners then adjourned to the 30th of 
November next, to meet at the city of Philadelphia; but 
agreed that if the mathematicians should arrive long 
before the 30th of November, the meeting should be on 
such other earlier day as the respective Governors, by 
letter should agree on, and at any other place than the 
city of Philadelphia, if it should be more convenient for 
the entering upon their work." 

Under date of December 1st, 1763, at a meeting of 
the commissioners, it is noted that the articles of agree- 
ment were read between Lord Baltimore d^ Thomas and 
Richard Penn, and Charles Mason and Jeremiah Dixon, 
bearing date the 4th day of August last, directed to 
their commissioners ; " also, a commission to the said com- 
missioners, recommending it to them to take to their aid 
and assistance the said Charles Mason and Jeremiah 
Dixon, and employ them to mark, run out, settle, fix, and 
determine all such parts of the circle, marks, lines, and 
boundaries as are mentioned in the several articles of 
agreement or commissions, and are not yet completed. 
Likewise a paper of hints given by Dr. Bevis and Mr. 
Harris to Lord Baltimore, and Thomas and Eichard 
Penn, referred and recommended to the consideration 
of their respective commissioners, and then adjourned 
to to-morrow," &c. &c. 

Thus we are introduced to Messrs. Mason and Dixon, 
who superseded the former surveyors in the employment 
of marking out these boundary lines. They immediately 



27 

entered upon their duties, and were employed in tracing 
and marking the several lines already described* until 
the 26th of December, 1767, when they were honorably 
discharged. Of the work of their predecessors, the run- 
ning of the due west line from Cape Henlopen to its 
termination midway between said cape and the shore of 
Chesapeake Bay, the trace and measurement of the radius 
of twelve miles from New Castle court house, and the 
determination of the tangent point in the circle, only 
were accepted as settled. The lines traced by their pre- 
decessors in their attempts to run the tangent line, a line 
of eighty two miles nearly in length, were, however, of 
great aid to Messrs. Mason and Dixon in finally estab- 
lishing that hue. In tracing it, by aid of the transit 
instrument, through a vista which they had opened in 
1764, which was. assumed by calculation to be the true 
tangent line, Messrs. Mason and Dixon constantly note 
how far, at every five mile post, their Hne passed from 
the posts previously set by their predecessors. 

In their minutes of survey they say: ^^ November 10th, 
1764. Produced the line to the point shown us (in the 
direction of the radius of twelve miles from New Castle, 
mentioned in the minutes of the 25th and 27th of 
August), to be the tangent point settled by the former 
surveyors, and measured the distance of our line from 

* The line west from the north extremity of the due north line was 
not prolonged as far as five degrees of longitude from the Delaware by 
Mason and Dixon. On reaching a point two hundred and thirty miles, 
eighteen chains and twenty-one links west of the extremity of the due 
north line, their further progress was arrested by the Indians. 



the said pointy and found it was sixteen feet seven inches 
to the eastward of the said point. 

" We continued our hne fifty-two and a half yards, and- 

T 
then it was opposite the post marked j^jj, and found we 

were sixteen feet from the said post eastward. 

"We also continued tlie line forty-one and a half yards 
farther, and then we were opposite the post marked T P, 
and then we measured the distance of our hne from the 
said post, and found it was fifteen feet two and a half 
inches to the eastward. 

'' November 12. Sent two expresses, viz: one to his 
Excellency Horatio Sharpe, Esq., Governor of Maryland, 
and the other to the Hon. James Hamilton, Esq., to 
acquaint them we finished our second line on Saturday 
last. 

^^ November 13. From the data in the minute of the 
27th of August we computed how far the true tangent 
line would be distant from the post shown us to be the 
tangent point, and found it would not pass one inch to 
the westward or the eastward. 

"On measuring the angle formed by our last line -and 
the radius from New Castle, it was so near a right angle 
that, on a mean from our hues, the above-mentioned 
post is the true tangent point. 

"From the whole we conclude that the offset posts in 
our second line, marked M D, are (as near as practica- 



in the true tangent line. 



CHARLES MASON, 
JEREMIAH DIXON." 



29 

From the record of proceedings of the commissioners, 
the following is an extract : — 

<• Saturday, Novemher 24:th, 1764, 

"The commissioners met according to adjournment. 

"Present as yesterday [namely: Horo. Sharpe, John 
Leeds, John Barclay, Dan. of St, Thomas Jenifer ; Ben- 
jamin Chew, John E^ving, Edward Shippen, Jr., and 
Thomas Willing]. 

"The commissioners, having resumed the considera- 
tions of yesterday, 

" Agreed, That the post set up by Messrs. Mason and 
Dixon, and by them marked West, shall be and be 
deemed and accounted fifteen miles south of the parallel 
of the most southern bounds of the City of Philadelphia, 
and that Messrs. Mason and Dixon shall be instructed 
immediately to proceed in running the west line directed 
by the articles from the said post till it reaches the 
river Susquehannah, where an observation shall be made 
by them. 

" Agreed cdso, That the post set up in the extremity 

of the radius of twelve miles from New Castle, marked 

M 

;j^jj, shall be and be deemed and accounted to be the 

true tangent point, and that the surveyors shall proceed 
to run the north line, and such part of the circle as falls 
to the westward of the said line, according to the articles, 
from the said point, as soon as they have run the said 
west line to the river Susquehannah, 

^'^ Agreed also, That the posts set up by Messrs, Mason 



30 

and Dixon at the eastern extremities of the offsets made 
from the line they first run from the point marked 
MiDDLEj and by them marked M D, shall be and be 
deemed and accounted to stand in the direction of, and 
to mark and describe the tangent line. 

''^Agreed lastly, That as soon as the surveyors shall 
have run the said west line to the river Susquehannah, 
and the said north line and part of the circle, stones 
shall be set up marked with the arms of the Lord Balti- 
more on one side, and the arms of the proprietors of 
Pennsylvania on the other, as the articles require and 
direct, along the said tangent line, in the places where 

the offset posts stand therein, at the tangent point marked 

M . 
;jrjj in several points of the periphery of the circle, in 

the north line, at the point where the said north line 

shall intersect the said west line, and along the said west 

line to the river Susquehannah, to be and remain as 

marks and boundaries forever, between the said province 

of Maryland and the counties of New Castle, Kent, and 

Sussex, on Delaware, and between the said j)rovince of 

Maryland and the province of Pennsylvania, as far as 

the river Susquehannah." 

The commissioners then agreed to give instructions 

pursuant to the foregoing agreement, and did so ; and 

then adjourned over to the 16th of June next, then to 

meet at Christiana Bridge. 

" Christiana Bridge, June 16, 1765. 
" The commissioners met according to their adjourn- 
ment of November 24th last," &c. &c. 



^1 

Commissions were read from the proprietors, prolong- 
ing the time for running the lines to the 31st December, 
1765, &c. &c. 

" Adjourned to to-morrow morning, ten o'clock." 



" Christiana Bridge, June 17, 1765. 

" The commissioners met," &c. &c. 

" The surveyors produced to the commissioners their 
minute books, which being compared, examined and found 
to agree, it appears thereby that in pursuance of the in- 
structions given them the 24th day of November last, 
they have extended the west line to the west side of the 
river Susquehannah, run a north line from the tangent 
point to intersect the said west line, and also described 
such part of the circle round New Castle as falls west- 
ward of said north line. 

" The commissioners approving of the lines run by the 
said surveyors, agreed to have a stone (the only one 
they have at present, on which are graven the arms of 
the respective proprietors), immediately fixed at the said 
tangent point ; another stone at the point where the above 
mentioned west line and north line intersect each other ; 
one other stone in the said north line, without the peri- 
phery of the circle ; one at the point where the north 
line and circle intersect ; and three others at different 
places in the said circle. The six last-mentioned stones 
to remain only until others more proper for the purpose, 
and with the arms of the right honorable the Lord Bal- 



timore, and the honorable proprietors of Pennsylvania^ 
graven thereon, can be procured. 

" And then adjourned to to-morrow morning." 

" Newark, June 18, 1765. 

" The commissioners met according to adjournment. 
Present as yesterday ; and went and fixed a stone, marked 
with the arms of the lord proprietary of Maryland on 
the west, and the arms of the proprietors of Pennsyl- 
vania on the east side of it, in the tangent point ; and 
also set up stones at the other places, according to their 
agreement of yesterday;" after which they gave Messrs. 
Mason and Dixon instructions to proceed with the run- 
ning of the west line westward of the Susquehannah, as 
far as the provinces of Maryland and Pennsylvania are 
settled and inhabited, unless obliged to desist on account 
of severe weather, or they should before that time re- 
ceive instructions to desist from their work. 

" The commissioners then adjourned to meet," &c. &c. 

" Thursday, JSfovemher 20, 1766. 

" The commissioners met," &c. &c. 

" Present as yesterday, [namely : John Barclay, Dan. 
of St. Thomas Jenifer, J. Beale Bordley; William Allen, 
Benjamin Chew, John Ewing and Thomas Willing.] 

:*: ^ ^ ^ ^: ^ 

" Messrs. Ewing and Barclay report to the other com- 
missioners, that in pursuance of their agreement, by their 
letters of the 5th and 22 d of October last, thirty-one 



33 

stones have been set up at a mile's distance each, in the 
tangent hne (in the places where posts had been fixed 
in the said line by Messrs. Mason and Dixon), from the 
fiftieth mile stone, set up formerly, to the tangent point ; 
each five mile stone being marked with the arms of the 
right honorable Lord Baltimore on the west side, and the 
arms of the honorable proprietors of Pennsylvania on 
the east, and the other intermediate stones, with the let- 
ter M on the west side and the letter P on the east. And 
the better to distinguish and ascertain the tangent point, 
another stone, marked with the arms of Lord Baltimore 
on the west side, and of the proprietaries of Pennsyl- 
vania on the east, hath been set up at the south side of 
the stone fixed in the said tangent point, by the commis- 
sioners on the 18 th of June, 1765. 

" That one stone, marked with the letter M on the west 
side, and the letter P on the east, hath been set up in the 
arc of the circle ; and three stones, marked as the latter, 
have been set up in the north line from the tangent 
point, in the places where Messrs. Mason and Dixon had 
set up mile posts in those lines : 

" That sixty-four stones have been set up in the west 
line, the first of which stands at the distance of one 
mile to the westward of the stone fixed by the commis- 
sioners, on the 18tli of June, 1765, in the point where 
the west and north Hues intersect, and the others at the 
same distance from each other, except at the end of sixty- 
four miles, where a proper stone was wanting, and is to 
be fixed at a future time, each five mile stone having 
the arms of the Lord Baltimore graved thereon, on the 



34 

south side, and the arms of the proprietors of Pennsyl- 
vania on the north, and the intermediate stones marked 
with the letter M on the south, and with the letter P 
on the north side." 

The rest of the proceedings of this meeting relate to 
the completion of the west line, and to obtaining the 
consent of the Indians to its being continued, &c. &c. 
Then the commissioners adjourned to meet at Chester- 
town, Maryland, on the 19th of March, 1767, or such 
earlier or later day as the commissioners may by letter 
agree on. Their next meeting did not, however, for 
reasons stated, take place until the 16th day of June, 
1767. On that day the commissioners met. Sir Wil- 
liam Johnson, his Majesty's agent for Indian affairs, had 
obtained the consent of the Indians to the tracing of the 
west line to its western extremity, that is to say, till it 
should reach to a distance of five degrees of longitude 
west from the river Delaware. 

On the 18th of June, 1767, the commissioners met, 
and gave to the surveyors their instructions for con- 
tinuing the trace of the west line to five degrees of longi- 
tude west from the river Delaware, in the parallel of the 
said west line, and cautioning them in regard to a con- 
ciliatory and proper conduct towards the Indians. 

" Friday, Decemher 25, 1767. 

" The commissioners met according to adjournment," 
&c. &c. 

" The sjirveyors' books were read, compared, and found 
to agree, by which it appears that they have extended 



35 

the parallel of latitude, agreeable to the instructions 
given them, by the commissioners on the 18th day of 
June last, to the distance of two hundred and thirty 
miles, eighteen chains, twenty-one links from the begin- 
ning of said hne, and two hundred and forty-four miles 
thirty-eight chains, thirty-six hnks from the river Dela- 
ware, near to a path called the Indian war path, but that 
they were prevented by the Indians deputed to attend 
them, by Sir WiUiam Johnson, from continuing the said 
Ime to the end of five degrees of longitude (the western 
limits of the province of Pennsylvania), which, in the 
latitude of the said line, they find, and the commis- 
sioners agree, to be two hundred and sixty-seven miles,* 
fifty-eight chains and ninety links, the said Indians al- 
leging that they were instructed by their chiefs in council, 
not to suffer the said hne to be run to the westward of 
the said war path," &c. &c. &c. 

On Saturday, December 26th, 1767, the commissioners 
met and approved the conduct of the surveyors, in de- 
sisting from the running of the parallel of latitude, upon 
the opposition made thereto by the Indians, to the fuU 
extent of five degrees of longitude from the river Dela- 
ware, pursuant to their former instructions. 

After describing the work thus far done, the commis- 
sioners agreed to discharge Messrs. Mason and Dixon from 

* From our better knowledge of the dimensions and figure of the 
earth, we should, at this day, compute these five degrees of longitude to 
be equal to two hundred and sixty-six and thirty-one hundredths miles, 
or two hundred and sixty-six miles, twenty-four chains and eighty links. 

J. D. G. 



36 

their service^ they having finished the hnes they were 
employed and sent over by the proprietors to run, under 
the direction of the commissioners, of which they gave 
the said Mason and Dixon notice, but agreed to make 
them satisfaction for a draft or plan they were instructed 

to prepare. 

^ ^ ^ ^ ^ ^ 

The commissioners adjourned to meet at Chestertown, 
Maryland, the 2 2d day of March, 1768, or such other 
day as they may by letter agree upon. 

After several meetings and adjournments of the com- 
missioners, the proceedings of which are not necessary 
to be noticed here, they met on 

Saturday, November 5, 1768. 

When "Mr. Ewing and Mr. Bordley informed the 
other commissioners that, agreeable to the desire of the 
commissioners, they have set up two stones, that is to 
say, Mr. Bordley has put up one at the middle of the 
due west hne, run from Fenwick's Island [Cape Henlo- 
pen] across the peninsula to Chesopeak Bay, in the 
place of the post marked 'Middle.'* 

"Mr. Ewing has put up the other in the due west 
line, run in the parallel of latitude fifteen English statute 

* The latitude of this Middle Point was determined, from astro- 
nomical observations made in October 1766, by Messrs. Mason and 
Dixon, with a zenith sector of six feet radius, to be 38° 27' 34". These 
observations were published in the fifty-eighth volume of the Philosophical 
Transactions of the Royal Society of London, for the year 1768. 

J. D. 0. 



37 

miles south of the most southern part of the City of 
Philadelphia, at the intersection of the said west line 
with the meridian run from the tangent point; the said 
stones having the arms of Lord Baltimore graved on the 
south and west sides thereof, and the arms of the pro- 
prietors of Pennsylvania on the north and east sides 
thereof," &c. &c. &c. 

The following is an extract from the final report of 
the commissioners, made to the proprietaries of the two 
provinces, hearing date the 9tli of November, 1768, 
taken from the original records at Annapohs. It em- 
braces a notice of all the lines and boundaries run out, 
fixed, and determined, under their direction, as well as 
those run out by their predecessors, and adopted as true 
boundaries, viz : — 

^'Ist. We have completely run out, settled, fixed, and 
determined a straight line, beginnmg at the exact mid- 
dle of the due east and west line mentioned in the arti- 
cles of the fourth of July, one thousand seven hundred 
and sixty, to have been run by other commissioners, 
formerly appointed by the said Charles Lord Baltimore 
and the said Thomas Penn and Richard Penn, across 
the peninsula from Cape Henlopen to Chesopeak Bay, 
the exact middle of which said east and west line is at the 
distance of thirty-four miles and three hundred and nine 
perches from the verge of the main ocean, the eastern end 
or begiiming of the said due east and west line; and that 
we have extended the said straight line eighty-one miles 
seventy-eight chains and thirty hnks up the peninsula, 
until it touched and made a tangent to the western part 



38 

of the periphery of a circle drawn at the horizontal dis- 
tance of twelve English statute miles from the centre of 
the town of New Castle, and have marked, described, 
and perpetuated the said straight or tangent line, by 
setting up and erecting one remarkable stone at the 
place of beginning thereof, in the exact middle of the 
aforesaid due east and west line, according to the angle 
made by the said due west line, and by the said tangent 
line ; which stone, on the inward sides of the same, facing 
towards the east and towards the north, hath the arms 
of the said Thomas Penn and Richard Penn graved 
thereon, and on the outward sides of the same, facing 
towards the west and towards the south, hath the arms 
of the said Frederick Lord Baltimore graved thereon; 
and have also erected and set up in the said straight or 
tangent line, from the said place of beginning to the 
tangent point, remarkable stones at the end of every 
mile, each stone at the distance of, or end of, every five 
miles being particularly distinguished by having the 
arms of the said Frederick Lord Baltimore graved on 
the side thereof turning towards the west, and the arms 
of the said Thomas Penn and Richard Penn graved on 
the side thereof turning towards the east, and all the 
other intermediate stones are marked with the letter P 
on the sides facing towards the east, and with the letter 
M on the sides facing towards the west; and have fixed 
in the tangent point a stone with the arms of the said 
Frederick Lord Baltimore graved on the side facing 
towards the west, and with the arms of the said Thomas 



39 

Penn and Richard Penn graved on the side facing 
towards the east. 

" 2dly. That from the end of the said straight line or 
tangent point, we have run out, settled, fixed, and deter- 
mined a due north line, of the length of five miles one 
chain and fifty links, to a parallel of latitude fifteen 
miles due south of the most southern part of the City of 
Philadelphia, which said due north line intersected the 
said circle, drawn at the distance of twelve English 
statute miles from the centre of the town of New Castle, 
one mile thirty-six chains and five links from the said 
tangent point, and that in order to mark and perpetuate 
the said due north line, we have erected and set up one 
unmarked stone at the point where the said line inter- 
sects the said circle, three other stones at a mile distance 
from each other, graved with the letter P on the sides 
facing the east, and the letter M on the sides facing the 
west, between the said place of intersection of the said 
circle and the said parallel of latitude, and a third* 
stone at the point of intersection of the said north line 
and parallel of latitude; which last stone, on the sides 
facing towards the north and east, hath the arms of the 
said Thomas Penn and Richard Penn graven thereon, 
and on the sides facing towards the south and west hath 
the arms of the said Frederick Lord Baltimore graved 
thereon. 

" Mly. That we have run out, settled, fixed, and de- 

* This is evidently an inadvertent error in the original manuscript = 
It should be ^foiirtli stone, &c. J. D. Gr. 



40 

termined such part of the said circle as lies westward 
of the said due north line, and have marked and per- 
petuated the same by setting up and erecting four stones 
in the periphery thereof, one of which, at the meridian 
distance of one mile from the tangent point, is marked 
with the letter P on the east, and the letter M on the 
west sides thereof. 

"4^A?y. That we have run out, settled, fixed, and 
determined a due east and west line, beginning at the 
northern point or end of the said due north line, being 
the place of intersection of the said north line with the 
parallel of latitude, at the distance of fifteen Enghsh 
statute miles due south of the most southern part of the 
City of Philadelphia, and have extended the said line 
two hundred and thirty miles* eighteen chains and 
twenty-one links due west from the place of beginning, 
and two hundred and forty-four miles thirty-eight chains 
and thirty-six links due west from the river Delaware, 
and should have continued the same to the end of five 
degrees of longitude, the western bounds of the Province 
of Pennsylvania, but the Indians would not permit us. 
And that we have marked, described, and perpetuated 
the said west line, by setting up and erecting therein 
stones at the end of every mile, from the place of begin- 
ning to the distance of one hundred and thirty-two miles, 
near the foot of a hill called and known by the name of 

* This distance of two hundred and thirty miles eighteen chains and 
twenty-one links is erroneously printed two hundred and eighty miles, 
&c. &c., in M'Mahon's History of Maryland, vol. i. See p. 46. 

J. D. a. 



44 

Sideling hill, every five mile stone having, on the side 
facing the north, the arms of the said Thomas Penn and 
Eichard Penn graved thereon, and, on the side facing 
the south, the arms of Frederick Lord Baltimore graved 
thereon; and the other intermediate stones are graved 
with the letter P on the north side, and the letter M 
on the south side ; and that the country to the westward 
of Sideling hill being so very mountainous as to render 
it in most places extremely difficult and expensive, and 
in some impracticable, to convey stones or boundaries, 
which had been prepared and marked as aforesaid, to 
their proper stations, we have marked and described 
the said line, from Sideling hill to the top of the Alle- 
ghany ridge, which divides the waters running into the 
rivers Potowmack and Ohio, by raising and erecting 
therein, on the tops of ridges and mountains over which 
the said line passed, heaps or piles of stones or earth, 
from about three and a half to four yards in diameter, 
at bottom, and from six to seven feet in height; and 
that from the top of the said Alleghany ridge, westward, 
as far as we have continued the said line, we have set 
up posts at the end of every mile, and raised round each 
post heaps or piles of stones or earth, of about the diame- 
ter and height before mentioned. 

'^^ Lastly. That we have^ according to the said articles 
of agreement, made out, signed, and sealed a true and 
exact plan and survey, as well of the due east and west 
line, which was as aforesaid formerly run out by other 
commissioners, appointed under the before-mentioned 
articles of agreement of the tenth day of May, one 



42 

thousand seven hundred and thirty-two, and decree and 
subsequent order aforesaid, running across the aforesaid 
peninsula from the verge of the main ocean towards 
Chesopeak Bay, but stopping in the exact middle of the 
said peninsula, as of such parts of the said circle, lines, 
marks, and boundaries as have been marked, run out, 
settled, fixed, and determined, in manner aforesaid, by 
the respective commissioners who have been for that 
purpose appointed, subsequent to the before-mentioned 
articles of agreement of the 4th day of July, one thousand 
seven hundred and sixty, which plan and survey we have 
hereunto annexed. 

" In testimony whereof we have hereto set our hands 
and seals, at Chestertown, in the Province of Maryland, 
the 9th day of November, in the 9th year of the reign 
of our Sovereign Lord, George the Third, King of Great 
Britain, &c., and in the year of our Lord one thousand 
seven hundred and sixty-eight." 

Then follows the certificate placed upon the map, re- 
corded in the proceedings of that date, and the whole 
is signed by 

HOR'O SHARPE, WILL. ALLEN, 

J. RIDOUT, BENJAMIN CHEW, 

JNO. LEEDS, JOHN EWING, 

JOHN BARCLAY, EDW'D SHIPPEN, Jr. 
GEO. STEUART, " THOS. WILLING. 
DAN. OF. ST. THOS. JENIFER, 
J. BEALE BORDLEY. 

I have been thus full in the extracts and minutes from 
the original manuscripts at Annapolis, because they ap- 



43 

pear necessary to a clear understanding of the lines we 
were required to examine, and because we shall have 
occasion to refer to many of the facts therein set forth, 
as having an important relation to our own survey. 

On the 9th of November last I went to New Castle, 
and on the lOtli to Philadelphia, to obtain the instru- 
ments in depot there which were required for our sur- 
veys. On the 12th, having met your board in confer- 
ence, at Wilmington, Delaware, I was invited to prepare 
and present for your consideration and approval a de- 
tailed plan of the field operations necessary to the accom- 
plishment of the objects pointed out by you. I requested 
an opportunity of previously making a reconnoissance 
of the line and of the land-marks within the limits of 
the portion of boundary in question, which was assented 
to ; and on the same day I accompanied the board to 
Newark, Delaware, which was decided on as the most 
convenient head-quarters of the Engineers during the 
field operations. 

The loth and 14th of November were spent in 
making the proposed reconnoissances in company with 
your board. 

We proceeded to the north-east corner of Maryland, or 
point of intersection of the due north line with the parallel 
of latitude fifteen miles south of the parallel of the most 
southern limit of Philadelphia. This point is in a deep 
ravine, on the margin of a small brook, and near its 
source. The stone monument with the arms of Lord 
Baltimore and Thomas and Richard Penn graven there- 
on, which had been placed by commissioner Ewing, by 



44 

order of the board of commissioners in 1768, to desig- 
nate this point, was missing.* From the tradition of the 
neighborhood, it appeared that some years ago, after it 
had fallen nearly prostrate from its place, owing to the 
encroachment of the stream, upon whose margin it 
stood, some individual had taken it away for a chimney- 
piece. A stake was found firmly planted in the ground, 
which, we were informed by the neighbors near by, oc- 
cupied its place. 

From this point we proceeded to the west, and found 
the first, second, and third mile stones on the parallel of 
latitude, marked with the letter M on the south, and the 
letter P on the north sides, as described in the proceed- 
ings of the commissioners of boundary of that period. 
The first of these stones was much inclined in its pos- 
ture, and somewhat infirm. 

We next proceeded to examine the line south from 
this corner, with the view of ascertaining if the stones 
at the intersection of the due north line with the peri- 
phery of the circle, and at the tangent point, were stand- 
ing. We extended our examinations to the south, upon 
the tangent line, as far as the seventy-ninth mile stone 
from the " Middle Point" of the peninsular line. We 
found a number of stones on the line, some unmarked, 
which we supposed to be on the circumference of the 
circle. With a radius of twelve miles, such a curve is 
so flat that it is difficult in walking over ground inter- 

* See the proceedings of the Commissioners, under date of November 
5th, 1768; noticed at page 36. 



45 



sected with forest timber, fences, and other obstructions, 
to distinguish, without the aid of instruments, the deflec- 
tions of the hues connecting monuments on its circum- 
ference nearly a third of a mile ajoart. Two of the 
monuments visited were graven on their east and west 
sides with the arms so often described in the preceding 
documents. One of these was near Jesse Updegrove's 
house, and the other in Mr. Heynolds's field, just north of 
the railroad track. 

This last I supposed to be the stone erected to mark 
the tangent point, as the arms were graven upon it, and 
it was much less than five miles (indeed, not quite 
three miles), from the preceding one, marked in a simi- 
lar manner to the southward. The nearest neighbors 
possessed no knowledge whatever of the particular point 
intended to be marked by this stone. A vague impression 
prevailed that it did not now occupy its original position, 
but that it had been disturbed at some distant but un- 
known period. On questioning the individuals who en- 
tertained this impression as to their reasons, it was stated 
that within the recollection of some of the inhabitants, 
fragments of stone, similar both in quality and in cut- 
ting to the portion now seen above ground, lay strewed 
at its base. The inference was that the stone was frac- 
tured near its base when taken up, and that the fragments 
seen were originally a portion of it. An impression 
likewise prevailed that the stone originally planted at 
the point of intersection of the due north line with the 
arc of the circle of twelve miles radius, corresponding at 
this day with the true point of junction of the three 



46 

States of Pennsylvaniaj Maryland and Delaware, was 
also missing. 

These were points that could only be settled by an 
accurate survey of the portion of the boundary involved 
in doubt or uncertainty, and then comparing the result 
with what ought to exist in conformity with the minute 
details contained in the recorded proceedings of the old 
commissioners and of their surveyors. 

Tliis course was suggested to your board,- and met 
your approbation. 

On consultation with the board, and by its approba- 
tion, I immediately called to my assistance Lt. Thom, of 
the Topographical Engineers, and Mr. Charles Eadzi- 
minski, civil engineer, who were assisted by Mr. Henry 
C. Derrick as sub-assistant; and the requisite chain bear- 
ers, axemen, &c., and means of transportation on the 
line, having been provided by you, the survey was com- 
menced on the 16th of November, with a portable tran- 
sit instrument having an azimuth circle for measuring 
horizontal angles, divided to read by aid of the vernier 
to minutes, and a chain of one hundred feet, divided into 
one hundred links of a foot each, and a standard five 
feet rod, of wood, with which the chain was compared 
several times every day, in order to reduce the chaining 
to correct measure. 

It was necessary, in this survey, and upon the maps 
designed to accompany it, that we should exhibit a por- 
tion of the tangent line, in order to lay down its true 
point of intersection with the due north line, for the 
purpose of testing the tangent point. Accordingly we 



47 

began at the stone marking the seventy-ninth mile of 
Mason and Dixon, reckoned from the middle point of 
the peninsular west line, having the Tetter M engraved 
on the west and the letter P on the east side ; and run- 
ning northerly to a signal placed at the base of the 
eightieth mile stone, we thus obtained the direction of 
the tangent line. This eightieth mile stone is en- 
graved with the arms of Lord Baltimore and the Penn 
family on the west and east sides respectively, precisely 
as described in the old records. Continuing in this initial 
direction, by the aid of the transit, our line passed im- 
mediately over the eighty-first mile stone of Mason and 
Dixon, engraved with the letter M on the west and the 
letter P on the east side, and also immediately over the 
next stone, which, being engraved with the arms of Lord 
Baltimore on the west and with the arms of the Penn 
family on the east side, was recognized to be the tangent 
point. 

We here deflected at a trial angle of 3° 32' to the 
eastward of the prolongation of our previous line, and 
pursuing accurately a straight course, we passed four 
stones on our left, to which offsets were measured, at 
right angles to our line. The first, second, and fourth of 
these stones were unmarked, but were cut in prismatic 
form, and rounded at their tops. The third, which at 
the distance of five thousand one hundred and fifty 
feet from the tangent stone was 95.3* feet perpendicular 

* This offset becomes 101.4 feet from the due north line; as will here- 
after appear. 



48 

and to the west from our line, was marked with the let- 
ter P on the east side and the letter M on the west side, 
and is the stone mentioned in the report of the commis- 
sioners of November 9, 1768, as being at the meridian 
distance of one mile from the tangent point. 

These four stones were now recognized to be those 
described in the proceedings of the commissioners of 
June 17 and 18, 1765, already quoted, and in their afore- 
said report (see page 39), as marking the arc of the 
circle of twelve miles radius, west of the due north line. 
It seems they were never substituted by stones bearing 
the arms of the proprietaries, as was contemplated to be 
done at some subsequent and convenient period, when 
they were planted by the commissioners in 1765. 

At the distance of 7,743.7 feet from the tangent stone, 
we reached an unmarked stone. Our trial line termi- 
nated nine feet west of it, measured at right angles to 
the line we had run upon. This stone was recognized 
to be the point marked in 1765 for the intersection of 
the due north line with the periphery of the circle of 
twelve miles radius, and stood now for the point of junc- 
tion of the three States. 

At every five hundred feet from the tangent stone, and 
also opposite each of the stones on the arc of the circle 
to which offsets were made while running this experi- 
mental line, we had driven a wooden stake. These were 
regularly numbered from one to nineteen inclusive. We 
now computed the angle at which we should, at the 
tangent stone, have deflected to the right from the pro- 
longation of the tangent line, to obtain the true direc- 



49 

tion, in a straight line, to the stone intended by Messrs. 
Mason and Dixon to mark the intersection of the due 
north hne with the periphery of the circle, and found it 
to be 3° 36' 09". 

By computation we also determined the points, and 
drove a new line of stakes ojDposite to the former ones, 
to mark this true direction, and determined the lengths 
of the offsets to the stones on the arc of the circle at 
right angles from the said new line. 

Taking up the new direction, obtained by computation, 
we continued our survey to the north, noting the topo- 
graphy, and carefully measuring offsets to the right and 
left, to all houses, fences, streams, and other remarkable 
objects within a reasonable distance, as indeed we had 
done from the beginning of the survey. 

Our line passed over three boundary stones marked 
with the letter P on the east, and with the letter M on 
the west sides, corresponding with the description given 
by the commissioners in their report, and by Mason and 
Dixon in their notes of survey, of the three stones on 
the due north line, north of the portion of the circle run 
out and fixed by them; and at its termination, our line 
passed immediately over the stake already mentioned as 
having been found by us in our reconnoissance of the 
13th of November, which was said to mark the point 
where the old stone had stood, at the intersection of this 
due north line with the east and west line of Mason 
and Dixon, marked with the arms of Lord Baltimore 
and the Penn family. We did not deviate two inches 
to the right or the left of the centre of this stake. It 
4 



50 

was on the 20th of November that our survey reached 
this point. 

On the following day we proceeded to find the true 
point of intersection of the east and west line of Mason 
and Dixon with this due north line. 

Beginning at the second mile stone west of the required 
point on Mason and Dixon's parallel of latitude, we 
traced out this parallel due east, and at the distance of 
five thousand two hundred and ninety-five feet, by our 
measurement, we touched upon the first mile stone on 
this parallel. Continuing upon the same parallel of 
latitude, at the distance of five thousand two hundred 
and eighty-two feet, by our measurement, from the pre- 
ceding stone, we struck the same stake at which our 
north line had terminated, at a point about one inch 
north of its centre. 

This last line traversed portions of thick forest, through 
which we were obliged to open vistas -, and in several 
places trees of large size, standing in open ground, had 
to be cut down to admit of its prolongation, which proved 
that there could have been no retrace of it until now, 
since the days of Mason and Dixon. 

Having thus, by the intersection of the due north line 
with the parallel of latitude, found the true position of 
the lost monument, we proceeded to mark and perpetuate 
it by planting the new monument, which had been pre- 
pared under the immediate direction of your board for 
that purpose. 

Before making the necessary excavation, the point to 
be occupied by the centre of the base of the stone was 



51 

preserved by placing four pegs nearly in the form of a 
square, so that the intersection of their diagonals should 
correspond with the said point. The next step was to 
construct a dam to turn off the water of the small brook 
which washed almost the very point, and thus prevent 
its filling the cavity. 

In making the excavation, we found at the depth of 
about three feet below the surface a cut stone unmarked, 
and of precisely the same form, dimensions, and quahty 
as the unmarked stones on the arc of the circle, and at 
the intersection of the circle with the due north line, 
already described. 

In turning to the proceedings of the commissioners, 
under the dates of the 17th and 18th of June, 1765, we 
find that such a stone was placed by them, to mark that 
point, on the last mentioned day. — (See pages 31 and 32.) 

It was not until the year 1768, that a second stone, 
marked with the arms of the proprietaries, was also 
placed at this point, as wiU be seen by the records of the 
proceedings of the commissioners of that date. — (See 
pages 36 and 37.) 

It is quite within the memory of the neighboring in- 
habitants that the stone which stood at this point in a 
tottering posture, to within a few years past, bore the 
arms, so often described, graven upon it. 

The unmarked stone of 1765 had probably been 
buried at the base of the one bearing the arms, when the 
latter was placed at the same pomt by commissioner 
Ewing, in 1768. 

The evidence afforded by the disinterment of this old 



52 

stone, that the point fixed upon from our survey, as the 
intersection of the due north line with the parallel of 
latitude fifteen miles south of the most southern limit 
of the city of Philadelphia, being the north-east corner 
of Maryland, corresponds so well with that originally 
established by Messrs. Mason and Dixon, is certainly 
gratifying. 

The new stone re-marking this important point was 
planted with its base resting on rock, about five feet 
below the surface of the ground, and its top rising about 
two feet above the ground. It is of cut granite, and of 
the following dimensions, viz., about seven feet long, and 
squares sixteen by eighteen inches. It is marked with 
the letter M on the south and west sides, and the letter 
P on the north and east sides. — Under this letter, on 
the north side, the date 1849 is engraved in deep cut 
figures. 

The striking discrepancies between some of our mea- 
sured distances and those of Messrs. Mason and Dixon, 
and their bearing upon the demarcation of the arc of 
the circle west of the due north line, as well as upon the 
true relative positions of the tangent stone, and the 
stone representing the intersection of this circle with the 
due north line, renders it proper that we should here 
institute a comparison between them, with a view, 
especially, to ascertain whether the impressions which 
prevailed, that one or both of the last-mentioned stones 
had been removed from their original positions, were 
founded in reason. 

If it were true that these important monuments had 



53 

been disturbed, no approximate estimate could be formed 
of the extent of mischief thus perpetrated upon the 
boundaries, without such investigations as would lead to 
a discovery of their original and rightful positions. The 
ascertainment of the true point of junction of the three 
States was involved in this question, and this was the 
chief object to be investigated and adjusted under the 
especial legislation of those States authorizing your pro- 
ceedings. In regard to Delaware, an impression prevailed 
among her citizens that a considerable portion of her 
territory had been abstracted by the curtailment of her 
rightful radius of twelve miles around New Castle. The 
unlawful disturbance of these monuments, if true, might 
well have produced such an effect, and it lay within the 
powers delegated to you to correct the wrong, if it could 
be proven to be owing to such a cause. 

The comparison is embodied in the following tabular 
statement, viz : — 



54 



5^ 












2 C3 



(M O (M 

(TO CO (M 

+ +I 



00 

+ 



T— ( 

+ 



CO 

CO o o 



+ 



G<1 



ci o id 

CO CO -^ 



o 

lO 



CO 

CD 

of 



CO 

CO o o 






CO 

oi 



1— I T-1 O 



O CO 









«5 tw 



&0^ 



oTrd 
5^ 



Ml 



M 



03 



O 



— ;^ O? fH 



i^.l 



c3 '-^ 



OI 



iH 


-*-' 


fl5 


IJ 




o 


o 


CI 


li 




Oi 


'*-' 




nn 


<B 





■d 


fl 


■5 


O 


•5 ■« 


o 




m 




0) 

r1 


-tJ 




CO 00 


o 




r^ ^ 


ULl 


o 




-(-= -kJ 




02 


OJ 



6 



a t- c^ 



'r=^ ^CO 



o o ^ 
S^O o 



id 

1 I a 1 

o 

02 

, S , 

I 03 1 

>-> a 



"^ ^ O I- 



03 



-r '4-. 



-73 O 

^ _Q ?f^ <» O 



C5 O 
t- GO 






^3 



o3 pTj 



r§ fl 



O c3 ^ 



-u -4-3 o 



"=-1^,5 



02 -^ 



00 42 



f=4 



rt <» a .5 

H S O 1-5 

^^ ^^ 

- s ^ "^ 

O 02 O HD 



^ 



2 2 ^ ^__ 

i=l !=l c3 ., 'T3 
O _o CU g cq 

CO CO ^ r^ O 

^ ^ 'S 02 "^ 

"i'g §'~§,^ 
a a as a 

o o o (— 1 o 

!h ;-i ;h ^ 

fai) pR ^ fe 



(U m '^ O 

^ fc, .5 " 

bO S S - 

c > S 
cs s -r ^ 
t^ - ^< 
o °S = — 

C u ^ O 

lU ttf ^ o 

— (DC*"' 
O) >» C3 o 



(U I- S = 

■^ CO (u o 

o ^S -S 

Vi n nj >-. 

c c ^, . 

S ,5 _^ S 

2 e '^ 2 

-5 - ° S 

O _ .S D 

t: (D t. 'S 
cs o 

s « 



ft 



c^ 2-S 

O ^ 2 ^ 

o s'S 
S .2 W „• 

■r c3 a - 

, <V r^ r\ 

^ ft -2 

^ CD .ii; 

eC O OJ O 

<» -^ ^ ^ o5 
S" fe g OJ 

o s . £; tiB 



iS c8 .2 ■£ S 

m o o '^ 
^ 'g M S ft 
a. S-H 2 S 

* o « 5 t^ 

^ "5 "o Q 



55 

The first discrepancy to be investigated was in regard 
to the length of the chord of the arc cut ofi" by the due 
north line. 

We, therefore, retraced it by running a straight line 
from the tangent stone to the stone set by the old com- 
missioners to mark the intersection. In addition to the 
first measurement of this chord, already given, two others 
were carefully made. The following is a statement of 
the results of the three, viz : — 

By the first measurement, - - - 

By the second measurement, 

By the third measurement, - - - 

Mean of the three, _ _ - - 
Length of this chord, given by Mason 

and Dixon, is one mile, thirty-six 

chains and five Hnks, equal to - 

Our measurement is greater than the 
length given by Mason and Dixon by 

Again : Mason and Dixon state the meri- 
dian distance from the tangent stone 
to the marked or third stone on the 
arc of the circle to be one mile, or - 5,280 feet. 

Our measurement srives this distance, - 5,150 " 



7,743.7 feet. 


7,742.2 


u 


7,743.1 


ii 


7,743. 


u 


7,659.3 


ii 


83.7 


ii 



Our measurement is less than the dis- 
tance given by Mason and Dixon, by 130 



These differences not only cast, at the moment, strong 
suspicion upon the present positions of the tangent and 



56 

the intersection stones, but they also affect, in a very 

important degree, the elements of the circle, an arc of 

which was to mark a part of the boundary between 

Maryland and what is now the State of Delaware. 

We had computed the angle of deflection between the 

prolongation of the tangent line and the due north line 

to be 3° 36' 09" ; and the measurement of that angle 

afterwards, with the theodolite, verified sufiiciently the 

accuracy of that computation ; for we finally found it, by 

a number of measurements repeated on all parts of the 

limb of the instrument, to be 3° 36' 06". 

With this angle, and the length of the measured chord, 

the length of the corresponding radius was computed on 

the supposition that the stones on the arc of the circle 

truly marked that arc. 

Making c = the chord. 

d = the angle of deflection from the 

tangent line to that chord. 

T = the radius. 

-TTrr .„ 1 c . cosine d 

We will nave r = — ; — — — 

sine 2 d 

By this equation, with the angle of deflection above 
given, and the chord, as given by Mason and Dixon, of 
one mile, thirty-six chains and five hnks, the corre- 
sponding radius is eleven miles and two thousand three 
hundred and two feet, or 11.44 miles. 

With the same angle of deflection, and the chord of 
seven thousand seven hundred and forty-three feet, which 
is the actual distance between the tangent and intersec- 
tion stones, the corresponding radius is eleven miles and 



57 

two thousand nine hundred and sixty-two feet, or 11.56 
miles. 

"We now made a trace of the curve upon the ground, 
corresponding to a radius of twelve miles. The lengili 
of a chord subtending an angle of one degree, at the 
centre of a circle of that radius, was computed to be 
1,1 5 /o feet ; and departing from the tangent stone by 
a deflection, in the first place, of half a degree from the 
prolongation of the tangent line, to obtain the first chord, 
and afterwards by deflections of a degree from chord to 
chord of the above-mentioned length, a number of points 
were obtained upon the circumference of the portion of 
the circle west of the due north Hue, which, thus traced, 
intersected the due north line two hundred feet in ad- 
vance, or north of the position of the stone placed, in 
1765, to represent that point of intersection. 

We next computed the length of the chord actually 

corresponding to the angle of deflection of 3° 36' 06", 

and a radius of twelve miles, by the equation 

r . sine 2 d 

G = 

cosine d 

and found it to be 7,960.6 feet, which is three hundred 
and one feet four inches longer than that given by the 
survey of Mason and Dixon, and two hundred and se- 
venteen feet five inches longer than the actual distance 
between the tangent stone and the intersection stone. 

In this state of the investigation, it was determined, 
upon my recommendation to your board, representing to 
you, at the same time, the necessity of the measure to a 
satisfactory solution of the problem involved, that the 



58 

actual length of the radius or distance from the spire of 
the court house at New Castle, to some point on the 
curve, as marked by the old monuments, should be ac- 
curately ascertained by a triangulation, which should be 
extended so as to give also the correct distances both 
from the tangent stone and the intersection stone, to the 
north-east corner of Maryland. The last-mentioned 
point, in case of any future disturbance of its monument, 
may always readily be found, as it is the intersection 
of two lines, both easily traced. Hence, knowing the 
distance from it to the other two, all three being upon 
the same meridian, a certain guide would be obtained 
for restoring either of the latter to its proper position, if 
disturbed. 

The distances given by the chain measurements of 
Mason and Dixon are already shown to be too inaccurate 
to serve for such a guide. 

On the 24th of November, I proceeded to Washington 
to ascertain if the records of the coast survey office could 
furnish us a distance, from its triangulation in this vici- 
nity, that would serve as a convenient base for our 
triangulation. And I have much pleasure here in ac- 
knowledging the courtesy and promptness with which 
Professor A. D. Bache, superintendent of that work, had 
the records examined, and furnished me, from them, 
several distances and azimuths which were determined 
some years past, when that work was under the superin- 
tendence of the late Mr. Hassler, and also, sketches of 
the localities of the several stations, to aid us in finding 



59 

the concealed monuments by which they were per- 
petuated. 

Some calculations had to be made in order to prepare 
them, and they were forwarded to me at Newark, on the 
9th of December, after my return to that place. 

Among them we found the following suitable to our 
object, viz : — 

1. From Iron Hill to New Castle court house: 

Distance, 16,281.57 metres.* 

2. From Gray's Hill to Iron Hill : 

Distance, 4,847.44 metres ;f 

Azimuth, 233° 48' 07".8.J 
The last-given distance was adopted as our base in 
the triangulation, and the necessary preparations were 
commenced for carrying it on with an excellent theodo- 
lite of nine inches diameter, § reading with three verniers 
to fifteen seconds each, made by E. Draper, of Phila- 
delphia. 

In the mean time, a retrace of the arc of the circle 
west of the due north line was carried on. 

* Equal to 53,415.1 feet. "I At the rate of 39.36850535 inclies to the 

f Equal to 15,903 feet. J metre, as adopted by the coast survey. 

I The azimuth is reckoned from the south as 0, round by the west, 
north, and east to the south, making 360°. 

§ On the 29th of January, while Mr. Radziminski was observing with 
this theodolite, during a violent gale of wind,. the heavy tripod station 
above him was blown over, and fell to the ground. It struck and de- 
molished the instrument, and Mr. R. narrowly escaped being killed; 
the largest timber just brushing his head, without, however, injuring 
him. This instrument was then substituted by another which I had ia 
depot at Philadelphia. 



60 

On the 9 th and 10 th of December it snowed heavily. 

On the 11th, the weather was clear, but very cold, 
with the snow nine inches deep upon the ground. The 
work was, however, prosecuted with assiduity, notwith- 
standing there was great difficulty in clearing the lines 
through the woods, in consequence of the weight of snow 
upon the branches of the trees. 

The second trace of this curve verified the accuracy 
of the first. The direction of the tangent line south- 
ward from the tangent stone, was also re-examined and 
verified. 

The engineers were then occupied in making the re- 
quisite reconnoissances of the surrounding country, in 
order to select suitable positions for our trigonometrical 
stations — in erecting those stations, and directing the 
opening of vistas through the interposing forest to ren- 
der those stations visible one from another. 

The severity of winter had fully set in. Notwith- 
standing this, the engineers were actively employed, 
whenever the weather was clear enough to see the sta- 
tions, in making the necessary observations ; and, when 
prevented from observing for want of a clear atmosphere, 
they were engaged in completing the erection of the 
stations and directing the clearings, a work which they 
forwarded with every possible assiduity, often in the 
rain and snow. 

The coast survey stations at Iron Hill and Gray's 
Hill, were discovered buried between two and three 
feet below the surface of the ground. They were not 
disturbed, but their centres were indicated in position 



61 

by the intersection of the diagonal lines of a quadrangle 
formed by four pegs, driven into the ground, about eight 
feet apart. Then the cavities were carefully filled again 
with earth, and a peg driven at the intersection of these 
diagonal lines to mark the extremities of our base line. 
In searching for the buried station at Gray's Hill, we 
could find only one of the points of reference given us 
in the sketches from the coast survey ofiice, with its 
distance from the station. 

The snow then lay six inches deep upon the ground, 
and the mode adopted to find this point was to take the 
stated distance on a cord line, and, attaching one end of 
it to the given point of reference, describe an arc of a 
circle covering the probable limits. 

The snow was then removed from this arc, and after- 
wards a trench was dug in the ground, following the 
curve until the station was found. 

The trigonometrical stations are all laid down in posi- 
tion on the accompanying maps; where, also, the whole 
triangulation is shown. These stations were marked 
upon the ground by tin cones fixed to the tops of stout 
poles, supported by tripods of heavy, undressed timbers^ 
giving them an elevation of sixty to seventy feet above 
the ground. The cones were adjusted perpendicular 
over the points marked upon the ground by short stakes, 
over which the centre of the theodolite was placed, when 
the angles were observed. 

The tangent stone, and the stone fixed at the north- 
east corner of Maryland, stood in such low depressions 
in the ground that stations could not be erected at 



62 

either of them high enough to be seen from the base 
stations, or, indeed, from any two of the other stations, 
suitable for fixing their positions. Two stations were, 
therefore, erected on the due north line, as near to them 
as possible ; one on the chord of the arc, at the measured 
distance of 1,701.02 feet north from the tangent stone, 
and the other on the due north line, at the measured dis- 
tance of 730.4 feet* south of the monument at the north- 
east corner of Maryland. 

The distance between the trigonometri- 
cal stations on the north line was 
found by our triangulation to be - 24,139.5 feet. 

Distance from the south station on north 
line to tangent stone (twice mea- 
sured), - 1,701.02 " 

From the north station on north line to 
the monument at the north-east cor- 
ner of Maryland (twice measured), - 730.42 " 



The sum = the distance from the tan- 
gent stone to the north-east corner of 

Maryland, 26,570.94 " 

Or, five miles and 170.94 feet. 

Deducting from the above our measured 
distance from the tangent stone to the 
intersection stone, - - - - 7,743 " 



We have the true distance from the in- 

* This is the chained distance, corrected to correspond with the point 
perpendicular under the cone. 



63 

tersection stone to the north-east cor- 
ner of Maryland, = - - - 18,827.94 feet. 
Or, three miles and 2,987.94 feet. 

The distance from the spire of the court 
house at New Castle to the station on 
the arc of the circle, which is the ac- 
tual radius of the circle, marking in 
part the boundary between Delaware 
and Maryland, was determined by 
our triangulation to be - - - 63,357.7 feet. 
Or, two feet and four inches less than the stipulated 

radius of twelve miles. 

During the investigations in relation to the arc west 
of the north line and its chord, I found it necessary to 
go again to Annapolis, in order to see if a further search 
into the notes of Mason and Dixon's survey would afford 
any explanations of the principles upon which they 
traced this arc, and determined the length of its chord. 
These notes, added to those of their predecessors, and 
the records of the commissioners of that period, were too 
voluminous for me possibly to finish their perusal and 
close examination within the period of my first visit. 

The information derived from them, combined with 
our determinations of the actual length of the radius, and 
the angle of deflection between the tangent line prolonged 
and the north line, served to elucidate the whole difficulty, 
which had arisen (where it was least to be expected) 
in an evident error in a governing element in their com- 
putation of the length of this chord, and, consequently, 
of the lengths of the ordinates at right angles to it, 



which was the method adopted by them for marking the 
points upon the arc west of the north Hne. 

The following is an extract from the records of their 
survey : — 

"1765, June od. Sent expresses to Annapolis and 
Philadelphia, to acquaint the commissioners we should 
finish the line betwixt the tangent point and the parallel 
this week. 

" Also measured the angle formed by the radius from 
New Castle and the north line, and found it = 86° 32'. 
Hence the offsets (at right angles) to the westward from 
the meridian for the boundary betwixt New Castle 
county and Maryland are as follows : — 



Distance from tangent 


Offsets. 






point. 










No. 


Chains- 


Links. 


Chains. 


Links. 










00 





00 




1 


8 


05 





46 




2 


18 


05 





92 




3. 


28 


05 


1 


28i 




4 


38 


05 


1 


54J 




5 


48 


05 


1 


70i 




6. 


58 


05 


1 


751 


" = the middle or greatest offset." 


7 


68 


05 


1 


70J 




8 


78 


05 


1 


54i 




9. 


88 


05 


1 


281 




10 


98 


05 





92 




11 


108 


05 





46 




12 


116 


05 





00 














CHA. MASON, 



JERE. DIXON." 



"1765, June itli. Set off the offsets, &c." 

We find, on investigation, that the foregoing elements 



65 

of the arc of Mason and Dixon are based upon the angle 
of deflection of the chord, from the tangent line produced, 
of 3° 28', or the complement of the angle, 86° 32', which 
they measured on the 3d of June, 1765, "formed by 
the radius from New Castle and the north line." It 
does not appear that they ever actually measured the 
angle between the tangent line (or its prolongation), 
and the north hne. That angle seems to have been as- 
sumed upon the supposed accuracy of their observation, 
noted in their survey book under date of November 
13th, 1764, as follows, viz: — 

"On measuring the angle formed by our last hne 
and the radius from New Castle, it was so near a right 
angle, that on a mean from our lines, the above-men- 
tioned post [the tangent post fixed by their predecessors, 

M 
and by them marked -j^jj] is the true tangent point." 

Now, the accuracy of that angle must have depended 
upon the coincidence of the exterior termination of the 
radius of twelve miles, with a perfectly straight line pro- 
longed from the court house at New Castle quite to the 
tangent point. This radius was determined by the sim- 
ple method of measuring over the surface of the ground 
with a surveyor's chain, for which purpose a vista, or 
" visto" as it was called by the surveyors in those days, 
was opened through the forest as the work progressed. 
We are surprised, at this day, that the length of the 
radius should have been so correctly obtained by such a 
method. There must have been, by mere chance, a 
compensation of the errors incident to such a measure- 
5 



66 

ment over so great a distance. Very small deviations 
from the true direction would not, however, produce 
much effect upon the distance, but this is not true with 
regard to the angle which would be formed between the 
tangent line and the radius, or the north line and the 
radius. A slight deviation in the direction of the radius 
at its termination, might affect, in a material degree, the 
measure of either of these angles, and we have reason to 
believe that the angle measured by Messrs. Mason and 
Dixon, between the tangent line and the radius from 
New Castle, which "was so near a right angle;" and 
" the angle formed by the radius from New Castle and 
the north line," which they found to be = 86° 32', were 
both affected by such an error. The tangent stone stands 
on low ground, very near the margin of a morass, known 
by the name of Cat Swamp. Looking from thence to 
the east, the ground is pretty flat for half a mile ; then 
it rises, by a rapid ascent, to the ridge running north- 
ward from the summit of Chestnut Hill, distant one 
mile. This ridge entirely shuts out the view of the 
whole country to the east of it, from the tangent stone, 
and must at least have limited the view of the radius, 
when the angles it formed with the tangent and north 
lines were measured by Messrs. Mason and Dixon. 

These angles were, then, probably affected by what- 
ever errors in direction may have arisen in running 
eleven miles of that radius from New Castle. 

Our own triangulation has given us the data for an 
accurate determination of the angle formed by the tan- 
gent line, and the line drawn from the spire of the court 



67 

house at New Castle, to the point of intersection at the 
tangent stone. 

From it we have — 

1. The angle at Iron Hill sub- 
tended by the spires of the court 
house and the church at New 

Castle, - - - - - =0°26' 13".3 = ci 

2. The angle at New Castle court 
house subtended by the stations 
on Iron Hill, and on the arc 

west of the north line, - - =5° 18' 31" = h 

3. Yalue of the arc of 63,357.7 
feet radius, included between 
the tangent stone and the trigo- 
nometrical station on the curve, 
whose chord was twice care- 
fully measured and found to be 

753 feet, - - - - = 0° 40' 51".3 = c 

4 . Angle of deflection between the 
tangent line and the north line 

or chord of the arc of boundary, =3'^36'06" = <:? 

And here we are again indebted 

to the coast survey records for 

the azimuth of the line from 

Iron Hill to New Castle church 

spire, which is given to be, - 261° 28' 33".9 = e 
Let the north-east angle formed 

by the tangent Hne and the 

radius drawn from New Castle 

court house to the tangent 

stone ~ X 



And the south-east angle, formed 

by the same lines - - - =y 

Then cc=a+(6— c)+e+c?— 180°=90° 08' 32".9. 
And^=360°— (a+(^— c)+c?+e) = 89°51'27'M. 

So that the tangent line does not form a right angle 
with the radius of twelve miles drawn from the spire of 
New Castle court house to the point occupied by the 
tangent stone. 

The angle, at the tangent stone formed by these two 
lines, differs 8' 32". 9 from a right angle. Now we find, 
by computation, that the small deviation of forty-six and 
one-half seconds in direction, or thirteen feet one and 
one-half inch from a straight line at the end of eleven 
miles, in running this radius from New Castle court house, 
would be sufficient to produce this difference of 8' 32". 9 
in the measurement of Messrs. Mason and Dixon's angle 
at the tangent post, supposing their view to the east to 
have been limited to the distance of one mile, as it evi- 
dently must have been from the nature of the ground. 

Even this is indicative of a very small error in direc- 
tion in tracing this radius, w^hen we reflect that it was 
prolonged through the forest by ranging staves or poles 
in line, one beyond another, as the surveyors advanced 
with their work, a method so inaccurate for tracing a 
straight hne that we are surprised it should have been 
resorted to in so important an undertaking. This was 
not, however, the work of Messrs. Mason and Dixon, 
but of their predecessors, who were less versed in science, 
and in the use of the higher order of geodetic instru- 
ments than were Messrs. Mason and Dixon. 



69 

That the arc of the circle west of the due north liiie 
and the radius terminating at the tangent stone, were 
traced and determined correspondent with one and the 
same centre, by the surveyors under the agreement of 
1760 and ourselves — that is to say, the spire of the court 
house at New Castle, is manifest from the following evi- 
dence and authority. 

The decree of Lord Hardwicke, of 1750, touches these 
two points, and the position of Cape Henlopen, in the 
following words, viz : — 

" And two questions in particular having been raised 
in America by the commissioners formerly appointed by 
the defendant, the Lord Baltimore, and being now made 
in this cause, namely, where the centre of the circle, 
agreed by the said articles [alluding to the agreement of 
1732], to be drawn about the town of New Castle there- 
in mentioned, ought to be fixed, and whether the said 
circle ought to be of a radius or semi-diameter of twelve 
miles, or only a jDcriphery of twelve miles ; and a third 
question being also made in this cause, namely, at what 
place the Cape called in the said articles Cape Hinlopen 
is situated, his Lordship doth declare that he is of opin- 
ion that according to the true intent and construction of 
the said articles, the centre of the said circle ought to be 
fixed in the middle of the town of New Castle, as near 
as the same can be computed, and the said circle ought 
to be of a radius or semi-diameter of twelve miles, and 
that Cape Hinlopen ought to be deemed and taken to be 
situated at the place where the same is laid down and 
described in the map or plan annexed to the said arti- 



70 

cles, to be situated. And, therefore, his Lordship doth 
further order and decree that the said articles be carried 
into execution accordingly," &c. &c. &c. 

The above extract is taken from the old parchment, 
bearing the original agreement of July 4th, 1760, with 
the autograph signatures and the seals of Frederick Lord 
Baltimore, Thomas Penn and Richard Penn, belonging 
to the Executive Department of the State of Pennsyl- 
vania, which instrument contains this as well as other 
recitals from the decree of 1750. 

In the body of that agreement are also found the fol- 
lowing words, viz : — 

"That the true length and extent of the said. line 
[alluding to the Hne across the peninsula from Cape 
Henlopen], was, and is, and shall at all times hereafter 
be esteemed, held, taken and adjudged to be sixty-nine 
miles and two hundred and ninety-eight perches, and 
neither more or less. That, consequently, the exact 
middle of such west line (from whence the other line is 
to begin which is to run up the said peninsula, till it 
makes a tangent to the western part of a circle, at the 
distance of twelve English statute miles horizontally 
measured from the Court House in the said town of 
New Castle), was, and is, and shall at all times forever 
hereafter be esteemed, held, taken and adjudged to be at 
the exact distance of thirty-four of the said miles and 
three hundred and nine perches, so measured west from 
the aforesaid spot or place of beginning of the said 
west line, as the same were so measured as aforesaid," 
&c. &c. &c. 

Here we have an especial recognition of the Court 



71 

House in New Castle as the point fixed on for the centre 
of the circle. 

The proceedings of the commissioners appointed on 
both sides, under the provisions of the agreement of 1760, 
and their instructions to the surveyors are even more 
exphcit upon this point. 

In the record of those proceedings, under the date of 
November 7th, 1761, we find the followinar : — 



-? 



" Satukday, the 7th of November, 1761. 
"Nine o'clock A. M. 

" The commissioners met according to adjournment. 

" Present as on yesterday. 

" The commissioners, having made their calculation, 
find that the tangent will, at the middle point, make an 
angle of three degrees thirty-two minutes and five 
seconds with the meridian line lately run by the survey- 
ors, and they agree that a radius of twelve miles, hori- 
zontal measure, shall be run from the centre of the 
Court House in New Castle, northwards of the line of 
intersection lately run from that place, so as to make an 
angle therewith of nineteen degrees three minutes and 
fifty-five seconds, which radius the commissioners find, 
by the calculations they have made, will terminate in 
the tangent point in the periphery of the circle. 

" Then the commissioners agreed to give the surveyors 
the following instructions, viz : — 

" Gentlemen : — You are to run a straight line of the 
leu2;th of twelve Enolish statute miles, horizontal mea- 



72 

sure, or as nearly horizontal as you can, from the centre 
of the Court House in New Castle, in such direction as 
to make an angle of nineteen degrees three minutes and 
fifty-five seconds northwards with the line of intersection 
lately run by you from the centre of the said Court 
House ; and at the end of such twelve mile hne you are 
to set up and secure a post or stone, at the same time 
making such visible marks near it, as may enable you 
hereafter to discover and determine its place, in case it 
should be destroyed or removed. And in order to pre- 
serve the direction of the said line, you are, also, at the 
end of six, ten and eleven miles from New Castle, and 
at the distance of twenty perches eastward of the end 
of such twelve mile line, to set up other posts in the 
said line. November 7th, 1761. 

J. KIDOUT, JAMES HAMILTON, 

JNO. LEEDS, RICHAI^D PETERS, 

JOHN BARCLAY, BENJAMIN CHEW, 

WM. COLEMAN." 

'' To Messrs. Thomas GtArnett, Jonathan Hall, John Lukens 
and Archibald McClean, Surveyors. 

" The commissioners adjourned to the first day of 
April next, at which time they agreed to meet again at 
New Castle. 

J. RIDOUT, . JAMES HAMILTON, 

JNO. LEEDS, RICHARD PETERS, 

JOHN BARCLAY, BENJAMIN CHEW, 

WM. COLEMAN." 



73 

We conclude the evidence on this point by quoting 

from the note book of the surveyors, who, in the year 

M 
1761, traced the radius and fixed the post marked -j^jj at 

its western extremity. It will be remembered that this 
is the post which the commissioners, in their proceed- 
ings of the 24th of November, 1764, declared, "shall be 
and be deemed and accounted to be the true tangent 
point, and that the surveyors shall proceed to run the 
north line and such part of the circle as falls to the west- 
ward of the said line, according to the articles, from the 
said point," &c. &c. 

The surveyors' records are as follows, viz : — 

" Saturday, JVovemher 7, 1761. 
"In pursuance of the last instructions, and also other 
directions from the commissioners, we this day went to 
the post near Joseph Tatloe's house, and from thence 
extended the direction of the line on which the base 
was measured for computing the distance from said post 
to the spire on New Castle Court House, to the distance 
of twenty-four chains sixty-three links and three-tenths 
of a link, thereby subtending an angle of 19° 3' 55" at 
the spire aforesaid, that being the angle which by the 
said last instructions we were required to make with the 
line of intersection ;* which said distance terminated in 
a point fixed on a white oak post well secured in the 

* Alluding to the first experimental line run from the court house to 
intersect a due north line which was traced up the peninsula from the 
''middle point" of the line run west from Cape Henlopen. 



74 

ground in the aforesaid direction, and found, by calcula- 
tion, to be seventy-five chains thirty-one links and 
seventy-six hundredths link distant from the spire afore- 
said, on the twelve mile line therein directed to be run. 

JNO. LUKENS, JONA. HALL." 



ARD. McCLEAN 



"November 8, Sunday, 1761." 

"November 9, 1761, Monday. 
"After ingaging sundry axemen this morning, Mr. 
Thomas Garnett, one of the surveyors on the behalf of 
iiis Lordship, having resolved to go home, and Jonathan 
Hall receiving advice that his wife was sick, thought 
proper to go home a few days, and there being none 
other here to act on the part of his Lordship, in running 
and measuring the line, which, by instructions of the 
seventh instant, we were directed to run and measure, 
we were, therefore, under the disagreeable necessity (not- 
withstanding we have divers persons in pay), to adjourn 
to the sixteenth of this month, at which time we agree 
to meet at New Castle, in order to run and measure the 
line as instructed. 

JNO. LUKENS, JONA. HALL." 

ARD. McCLEAN, 

" Monday, Novemler 16, 1761. 
" This morning early we met at New Castle, accord- 
ing to adjournment, and went to the post, which, by the 



75 

direction of the commissioners, we set in the ground on 
the seventh instant, at the distance of seventy-five chains 
thirty-one links seventy-six hundredths of a link, by 
computation from the spire of the court house of New 
Castle, and, after opening a visto toward the said spire 
from the point mentioned to be fixed in said post, we 
extended a line westward in the direction of said spire 
and point four chains sixty-eight links twenty-four hun- 
dredths of a link to a squared white oak post marked 
J ; which said post is found by the aforesaid computed 
and measured distances, to be one mile distant from the 
spire on said court house. 

JNO. LUKENS, JONA. HALL." 

ARD. McCLEAN, 

After detailing each day's work, in the prolongation 
and measurement of this radial line, the surveyors de- 
scribe its completion on the twenty-eighth of November, 
and its re-measurement between that date and the second 
of December, as follows, viz. : — 

" Saturday, November 28, 1761. 
"Proceeded with the line sixty-three chains, where 
we fixed and secured firmly in the ground in the mea- 
dow, late Lewis Thomas's, a squared white oak post 
marked -^jj; the said measure ending in a point fixed 
thereon, which said post, we are of opinion, is twelve 
English statute miles, horizontal measure, distant from 
the spire of the court house in New Castle, that being 



76 

the distance wliicli, by our instructions, we were enjoined 
to extend the said line, during the measure of which 
distance we kept the account in four-perch chains, though 
where hills intervened, the measure was performed by 
instruments, before prepared for rendering the same 
horizontal, and, where level, the same was taken by a 
two-perch chain, which we frequently and carefully mea- 
sured; and, after fixing the said twelve mile post, we 
took the courses and distances from thence to the several 
trees, as expressed on the next page,* thereby to deter- 
mine its place, in case it should be destroyed or removed ; 
afterward we fixed a white oak post in the said direc- 
tion, at the distance of twenty perches to the eastward 
of the said post; which done, we agreed to begin at the 
said twelve mile post and re-measure the line toward 
New Castle superficially, least a mistake should have 
been committed from the different modes we were obliged 
to pursue, or take, in order to make the measure hori- 
zontal, which re-measure we continued to the ten mile 
post, and left off. Afterward settled with and dismissed 
sundry of the laborers. 



JNO. LUKENS, JOHN F. A. PRIGGS 

APvD. McCLEAN, JONA. HALL." 



"November 29, Sunday." 

"Monday, November 30, 1761. 
"Continued the re-measure of the line (as on the 

* The next page of the old surveyor's book contains the diagram re- 
ferred to. 



77 

twenty-eighth instant), from the ten mile post to the 
two mile post, where night came on. 

JNO. LUKENS, JOHN F. A. PRIGGS, 

AED. McCLEAN, JONA. HALL." 

'' Tuesday, December 1, 1761. 

" Continued the re-measure as before from the two mile 
post to the post which we set up on the seventh ultimo, 
from which the direction of the line was taken, and, 
from the proportional agreement between the superficial 
and horizontal measure, find that no mistake hath been 
committed. 

" Settled with, and dismissed, the chain-carriers, and 
all the other hands except the steward and wagoner, 
then rode to Wilmington, there to take account of and 
deposit the stores for the winter season. 

JNO. LUKENS, JOHN F. A. PRIGGS, 

ARD. McCLEAN, JONA. HALL." 



'? 



" Wedjstesday, December 2, 1761. 
" This day took account of the stores ; stored them in 
Wilmington, in the care of John Stapler, Esq. ; settled 
sundry accounts, dismissed the steward and the wagoner. 

JNO. LUKENS, JOHN F. A. PRIGGS, 

ARD. McCLEAN, JONA. HALL." 

From the foregoing authorities, no doubt whatever 
can exist that the point agreed on and used as the cen- 
tre of the circle of twelve miles radius by the commis- 



78 

sioners and surveyors of Lord Baltimore, and Thomas 
and Richard Penn, was one and the same as that in 
reference to which the arc of the circle west of the due 
north line, and the radius terminating at the tangent 
stone, were traced and determined by us in our recent 
survey. 

The discrepancies, then, which have been shown be- 
tween our work and theirs, in regard to this arc and the 
angle formed between the radius and the peninsular or 
tangent line, at the tangent stone, cannot be attributed 
to any difference in our positions resjDecting the centre of 
this circle. 

The radius run out by the surveyors in 1761, indi- 
cated by a line drawn from the spire of the court house 
in New Castle, to the present position of the tangent 
stone, should be revolved about the centre of its circle 
(the spire aforesaid), through an arc of 8 minutes and 34 
seconds and one-tenth of a second to the south, and then 
produced two feet four inches westward, and the line 
called the tangent line, should be revolved westward 
about its southern extremity, at the " Middle Point" of 
the Cape Henlopen line, through the inappreciable angle 
of one second and two-tenths of a second, and then these 
two lines would meet at right angles, at the distance of 
157.6 feet southward from the present position of the 
tangent stone. 

The slight variation thus required in the azimuth of 
the tangent line, proves the surprising accuracy of its 
direction as determined by Messrs. Mason and Dixon, 
and how truly it divided the provinces, in accordance 



79 

with the articles of the ancient agreement, as far as it 
extended, which is given by Mason and Dixon in their 
notes of survey, to be 81 miles 78 chains and 31 links, 
or 17.2 yards less than 82 miles. 

It is equally surprising that there should have been 
so great an error in their elements for marking out the 
arc of the circle west of the north line, and in the length 
of their chord, which they computed to be 116 chains, 

and 5 links, or 7,659.3 feet. 

And which we find to be, as actually 
marked by the tangent and intersec- 
tion stones, 7,743 " 

But which, according to our computa- 
tions, should have been - - - 7,960.6" 

And should have begun at a point 157.6 feet southward of 
the present position of the tangent stone, and have ended 
at a point 143.7 feet north of the present position of 
the stone set by Mason and Dixon, and the commissioners 
of their day, to mark its termination, and constituting 
now the point of junction of the three States. 

The origin of this error has, we think, been satisfac- 
torily discovered. 

It is our opinion that the stones on the arc, west of 
the north line, stand as originally placed. Of this we 
have evidence, conclusive enough, from the lengths of 
our measured ordinates of that arc, compared with the 
3d, 6th and 9th in the table of Mason and Dixon, copied 
at page 64. 



80 



The following is a comparison of qur measurements with 
theirs for this arc. 



According to Mason and Dixon's survey 
made in 1765. 


According to our measurements on the 
ground in 1849. 




Distances on chord 

from tangent stone, 

in feet. 


Lengths of or- 
dinates, in feet. 


Distances on chord 

from tangent stone, in 

feet. 


Lengths of ordi- 
nates, in feet. 


1 

2 
3 


1,851.3 
3,831.3 
5,811.3 


84.8 

115.8 

84.8 


1,855.3 

3,836.7 

5,872.7 


85.4 
115.6 

84 



We can make no comparison with the marked stone on 
the arc intervening between the 2d and 3d of the above 
table, and which was intended to be put at the meridian 
distance of one mile from the tangent stone, for the 
reason that Mason and Dixon do not give the length of 
their ordinate for that one. 

We found it, however, to be 101.4 feet perpendicular 
from the chord to the west, and we find, by computing 
its place from the elements assumed by Mason and 
Dixon for marking this arc, that it would be 99.4 feet. 

The foregoing table shows conclusively that the tan- 
gent stone could never have been moved from its original 
position, for our first and second distances from it on 
the chord, or north line, correspond almost exactly with 
those given by Mason and Dixon, quite within the pro- 
bable errors of careful chaining at least. The discre- 
pancy in our distances to the third ordinate is no doubt 
owing to an error in the count of one chain (66 feet) on 
their part, for our distance was tested by three measure- 
ments. 

There is no doubt that that stone and the intersection 



81 

stone remain at this day in the positions given to them 
by the commissioners and surveyors in 1765. 

In addition to the above evidence, we have that which 
arises from the fact that they both now stand upon their 
proper lines of direction, which would scarcely have 
been preserved had they been moved by mischievous 
interference. The tangent stone stands now precisely 
upon the same right Hne, with the three monuments to 
the southward of it on the tangent line, and the inter- 
section stone stands as truly on the north line. The 
error in the distance intended to be given them apart by 
Messrs. Mason and Dixon (which accidental distance 
we actually found to be nearer the truth than their com- 
puted distance), was probably one of miscount in their 
chain measurement, as was also the error of one hundred 
and thirty* feet in the meridian distance of the marked 
stone on the arc from the tangent stone, which they 
state to be one mile. 

Those who beheved that the tangent stone had been 
disturbed in its position because of the fragments of stone 
of a similar character which for some time lay strewed 
at its base, were not carried so far back by tradition as 
the period when this point was marked by two similar 
stones, engraved alike with the arms of the proprietaries, 
and placed side by side, "the better to distinguish and 
ascertain the tangent point," as will appear was done by 
reference to the records of the commissioners under the 

* This error was probably caused by a miscount of two chains, which 
would be equal to one hundred and thirty-two feet. 

6 



82 

dates of June 18th, 1765, and November 20th, 1766, 
given in the preceding extracts and briefs of their pro- 
ceedings. 

The fragments which we were told of while engaged 
in the reconnoissances, were the remains, no doubt, of 
the missing companion of the one we found a little in- 
clined in posture, but firmly planted in the ground. 
When it was taken up, for the purpose of placing the 
new stone, which will presently be noticed, it was un- 
broken and perfect in its form. 

Had Messrs. Mason and Dixon adopted the method 
of tracing the arc by deflecting from their tangent line 
(which is so true in its direction), and then from chord 
to chord of a constant length, to find points on the cir- 
cumference of that arc, it would not have been affected 
by the want of perpendicularity in the assumed direction 
of the radius to the tangent. They would, by this 
method, have described the true arc, independent of any 
reference to the radius, except alone as to its length, 
and they would have intersected the north line by the 
curve at precisely the distance from the tangent stone 
computed by us, that is to say, at 7960.6 feet from it, 
and 217.6 feet in advance of its present position. 

The error in their curve is not one of moment, as re- 
gards extent of territory, as it abstracts from Delaware 
and gives to Maryland only about 1//^ of an acre. The 
versed sine of their arc is 115.8 feet, and that of the arc 
they should have traced is 125.3 feet. 

Although their measured distances are found to be 
affected by many errors, incident always to measure- 



83 

ments of great extent with the chain, yet the directions 
of their lines are correct, and as the only distance in- 
cluded in their portion of the survey, and specified as 
an element in the boundary, namely, the fifteen miles 
south of the parallel of the most southern limits of the 
City of Philadelphia was, after measurement with the 
chain, corrected by very accurate observations for the 
corresponding difference of latitude, the absolute division 
of territory between the then Provinces was effected 
from the south extremity of the tangent line to the north 
extremity of the north line, on the whole, with great 
accuracy. Their long west line or parallel of latitude 
we have had no occasion to test, except for a short dis- 
tance, but the great care with which their astronomical 
observations, contained in the old manuscripts at Anna- 
polis, were made, leaves no doubt of the accuracy of that 
part of their work. 

These observations, together with the records of the 
proceedings of the several joint commissions charged 
with the division of the then Provinces in question, will 
be more fully alluded to in a report to Col. Abert, Chief 
of the Corps of Topographical Engineers, and they will, 
I hope, be rescued from their long slumber in quiet ob- 
scurity, and be laid before the world in a printed form. 

The conclusion having been arrived at, that none of 
these monuments found on the curve, at the tangent 
point, and at the intersection point, had been disturbed 
in their original positions, which was ratified by your 
board, the obligation to consider them true marks of 
boundary is imposed by the declaration to that effect 



84 

by the commissioners acting on behalf of their respective 
constituents, Lord Baltimore, and Thomas and Richard 
Penn, fully expressed on the records of their pro- 
ceedings. 

Accordingly, by your directions, in addition to the 
new monument fixed at the north-east corner of Mary- 
land, as already mentioned, the following were also 
erected at the tangent point, at the intersection point, or 
junction, of the three States, and on the meridian of the 
curve, viz : 

At the tangent point, a post of cut granite, 6 feet long, 
and squaring 18 by 15 inches, was inserted 4 J feet of its 
length in the ground, on the north side of and touching 
the old stone bearing the engraved arms, which remains 
in its old position. On the north side of the new stone 
is graved, in deep cut letters, the word TANGENT, with 
the date 184®. 

At the point of junction of the three States, a trian- 
gular prismatic post of cut granite, 18 inches wide on 
each side, and 7 feet long, was inserted 4i feet of its 
length into the ground. It occupies the exact spot 
on which the old unmarked stone was found. It is 
marked with the letters M, P and D, on the sides facing 
respectively towards the States of Maryland, Pennsyl- 
vania, and Delaware. On the north side, below the let- 
ter P, are the names of the commissioners, in deep cut 
letters, namely: "H. G. S. KEY, of Md., J. P. EYRE, 
of Pa., G. R. RIDDLE, of Del., Commissioners," with 
the date 1849. This boundary stone stands upon land 
now belonging to Wm. Johnson. The old unmarked 



85 

stone was buried, Ij^ng in a prostrate or horizontal posi- 
tion, just below the surface of the ground, on the north 
side of and central with the new stone. 

At the meridian, or middle point of the arc, corre- 
sponding to the length of the chord, as we actually found 
it, and at the distance of 118.4 feet perpendicular from 
the middle point of said chord, a post of cut granite, 6 
feet long, was inserted 4* feet of its length into the 
ground. This stone squares 17 by 14 inches. It is 
rounded on the west side to indicate that it is on the 
curve, and on the east side the date 1849 is marked in 
deep cut figures. 

The circular boundary between Pennsylvania and 
Delaware, from the point of junction of the three States 
to the river Delaware being yet unmarked, and a num- 
ber of citizens residing near this common border being 
in doubt, and anxious to know to which State they be- 
long, at your suggestion the survey was conducted with 
such precision as to enable us to describe that boundary 
correctly, as will appear upon our map, for a distance of 
about of miles north-eastward from the junction. 

We have determined the distance by computation, at 
which a due east line from the north-east corner of Mary- 
land will cut that circular boundary and find it to be 
4036 feet, or .766 of a mile. We have also computed 
the angle with the meridian at the said north-east cor- 
ner, made by a line drawn from thence to the spire of 
the court house at New Castle, and find it to be 70° 20' 
45" east of south. At the distance of 3786 feet, mea- 



86 

sured on the said line from the aforesaid north-east cor- 
ner, this line will intersect the circular boundary. 

The want of a proper demarcation of the boundaries 
between States is always a source of great inconve- 
nience, and often of trouble to the border inhabitants ; 
and it is worthy of remark, that as our survey progressed, 
and while making the necessary offsets to houses on the 
east of the north line, we discovered that there was an 
impression among many, that the boundary of Delaware 
extended up to the north line, from the junction to the 
north-east corner of Maryland. 

Mr. W. Smith, a gentleman who has once served as a 
member of the Legislature of Delaware, resides a full 
half mile within the State of Pennsylvania, ^measured 
in the shortest direction from his dwelling-house to the 
circular boundary. 

We find, also, by careful measurement, that Christiana 
church is in Pennsylvania, full one hundred yards west 
of the circular boundary. The dwelHng-houses of 
Messrs. J. Jones, Thomas Gibson, Thomas Steel, and J. 
M'Cowan, are all within the bounds of Pennsylvania, 
according to our trace of the circle from computed ele- 
ments. 

I take great pleasure in acknowledging here the 
valuable aid rendered, in this survey, by my assistants, 
Lt. George Thom, of the Topographical Engineers, and 
Mr. Charles Kadziminski. 

The former was obliged, by his duties in the office of 
the north-eastern boundary, to return to Washington on 
the 24th of November. He joined us, however, again, 



on the 29 til of January, and participated in the com- 
pletion of the field work, on the 6 th of February, at a 
time when, owing to the delays which the almost con- 
tinued stormy and cloudy weather in January had pro- 
duced, his aid was very important. 

Mr. Radziminski remained in the field from the be- 
ginning to the end of the work, and used every exertion 
to forward it. Mr. Derrick, our junior assistant, did the 
same. They lost not a day that could be appropriated 
to the out-door work ; and often, when the weather was 
unpromising, they would go out, in order to be ready to 
observe angles, &c., if it should clear, and would return, 
drenched with rain, or covered with sleet, during the 
cold weather of December and January, never regarding 
their personal comfort, when the work could be forwarded 
by exposing themselves, 

I herewith present three finished maps, one for eacli 
of your respective States, constructed from our surveys, 
and duly certified.* 

All which is respectfully submitted. 

J. D. GRAHAM. 



* These maps are on a scale of 4 inches to 1 mile^ or j-gl^^- 

J. D. a. 



ERRATA. 

Page 24, 3d line from top, for " respecting" read " respective." 
" 39,23d " " "graven" rea(^ "graved." 

" 48, 9th " " "(see page 39)" read "(see pages 

39 and 40.)" 



The following notice of "Errata" is to be attached to the report of 
Colonel Graham of February 27th, 1850, communicated with the Gover- 
nor's message of March 13th, 1850, to the Legislature of Pennsylvania, 
and printed by its order, viz.: 

ERRATA. 

Page. Line 
from top. 
8 23 For "understrood" read understood. 

11 50—51 At the bottom of Note 1. Insert the name of BEN- 
JAMIN CHEW immediately after that of RICH- 
ARD PETERS, on the side of the Commissioners 
of Pennsylvania. 
11 57 Note 2. For latitude 39° 43' 32" read latitude 39° 

43' 18". 

For "theron" 7-ead thereon. 

For "Chanceller" read Chancellor. 

For "side" read sides. 

For "Edward Shipping, jr.," read Edward Shippen, jr. 

For "of said line" read of the said line. 

After -jj^jj put a comma. 

Erase the marks of quotation beginning with the 7th 
and ending with the 8th line. 

For "/oWy-eight chains" read fifty-eight chains. 

After the words "the eastern end" insert the words or 
beginning. 

For "line" read lines. 

After the word placed, add, in 1765. 

After the number 2,897.94 add the word/ee(. 

Let the marks noting the end of the quotation follow 
the first, &c.; then erase the second, (fee. 

For "trigonomical" read trigonometrical. 

For "proceeding" read proceedings. 

After the word as insert the word on. 

After the word on insert the word the, so as to read, on 
the behalf, &,c. 
34 46 For versed line, read, versed sine. 



12 


19 


12 


32 


12 


35 


14 


21 


14 


33 


14 


44 


15 


7—8 


16 


42 


17 


32 


19 


21 


25 


3 


27 


6 


28 


1 


28 


49 


30 


60 


30 


21 


31 


26 



